Listings 0056, 0057. Improve README

Add .LOOP instruction, dump memory to disk with cli arg
Listings 54 and 55
2025-06-14 10:31:35 +07:00 · 2025-03-23 08:58:29 +07:00 · 2025-03-23 08:58:12 +07:00 · 2025-03-22 18:54:36 +07:00 · 2025-03-22 15:21:47 +07:00 · 2025-03-22 15:20:48 +07:00
52 changed files with 56950 additions and 666 deletions
@@ -3,3 +3,6 @@
 /asm_files/*.bin
 /8086_family_Users_Manual_1_.pdf
 /decoder8086
+/performance-aware
+/sim8086
+/listing-*.data
@@ -1,8 +1,96 @@
 #+OPTIONS: toc:nil

-* 8086 CPU Emulator
-Following along with [[https://www.computerenhance.com/p/table-of-contents][Performance Aware by Computer Enhance]]
-* License
-This project is licensed under the terms of the MIT license. For more
-information, see the included LICENSE file. However, some of this is related to
-a paid course so maybe pay for the course if you want to use these files?
+* 8086 CPU Simulator
+
+A complete 8086 processor emulator written in Odin, featuring instruction decoding, execution, and cycle-accurate simulation. Implements a comprehensive subset of the Intel 8086 instruction set with proper flag handling, memory management, and register operations.
+
+** Features
+
+- *Complete 8086 instruction decoding* - Supports MOV, arithmetic, jumps, loops, stack operations, and more
+- *Cycle-accurate execution* - Proper CPU state management with registers and flags
+- *Memory simulation* - 1MB addressable memory space with effective address calculation
+- *Comprehensive testing* - 21 assembly test programs with automated validation
+- *Reference validation* - Compares execution results against reference CPU states
+
+** Architecture
+
+The simulator is organized into several focused modules:
+
+- =sim8086.odin= - Main entry point and program orchestration
+- =types.odin= - Core data structures (CPU state, instructions, operands)
+- =instructions.odin= - Complete 8086 instruction set definitions
+- =decoding.odin= - Binary instruction decoding and parsing
+- =execution.odin= - CPU execution engine with flag calculations
+- =printing.odin= - Assembly output formatting
+- =testing.odin= - Reference state parsing and validation
+
+** Building and Running
+
+#+BEGIN_SRC bash
+# Build the simulator
+make
+
+# Decode and print assembly
+./sim8086 program.bin instructions
+
+# Execute with register dump
+./sim8086 program.bin registers
+
+# Full execution with memory dump
+./sim8086 program.bin all dump
+#+END_SRC
+
+** Testing
+
+Comprehensive test coverage included:
+
+#+BEGIN_SRC bash
+# Run all assembly tests
+./test_asm.sh
+
+# Run reference CPU validation tests
+./test_ref_cpu.sh
+#+END_SRC
+
+Test files cover:
+- Basic MOV operations and addressing modes
+- Arithmetic and logical operations with proper flag setting
+- Jump and loop instructions
+- Stack operations (PUSH/POP)
+- Complex programs with multiple instruction types
+
+** Technical Implementation
+
+*** Instruction Decoding
+- Bit-level parsing of 8086 machine code
+- Support for all addressing modes (register, immediate, memory, direct)
+- Proper handling of prefixes and multi-byte instructions
+
+*** Execution Engine
+- Register file with proper 8/16-bit access patterns
+- CPU flags (Zero, Carry, Sign, Overflow, etc.) with accurate calculations
+- Effective address computation for memory operations
+- Instruction pointer management and control flow
+
+*** Memory Model
+- 1MB linear address space
+- Little-endian byte ordering
+- Memory-mapped I/O simulation
+
+** Supported Instructions
+
+*Data Movement:* MOV, PUSH, POP, XCHG, LEA, LDS, LES
+*Arithmetic:* ADD, SUB, MUL, DIV, INC, DEC, CMP, NEG
+*Logical:* AND, OR, XOR, NOT, TEST
+*Shifts/Rotates:* SHL, SHR, SAR, ROL, ROR, RCL, RCR
+*Control Flow:* JMP, JE, JNE, JL, JG, LOOP, CALL, RET
+*String Operations:* MOVS, CMPS, SCAS, LODS, STOS
+*System:* INT, IRET, HLT, NOP
+
+Built following the [[https://www.computerenhance.com/p/table-of-contents][Performance Aware Programming]] course by Casey Muratori.
+
+** License
+
+This project is licensed under the MIT License - see the LICENSE file for details.
+
+*Note:* Some test files are derived from the Performance Aware Programming course materials. Consider supporting the course if you find this project useful.
@@ -0,0 +1,451 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 42
+; ========================================================================
+
+;
+; NOTE(casey): This is not meant to be a real compliance test for 8086
+; disassemblers. It's just a reasonable selection of opcodes and patterns
+; to use as a first pass in making sure a disassembler handles a large
+; cross-section of the encoding. To be absolutely certain you haven't
+; missed something, you would need a more exhaustive listing!
+;
+
+bits 16
+
+mov si, bx
+mov dh, al
+mov cl, 12
+mov ch, -12
+mov cx, 12
+mov cx, -12
+mov dx, 3948
+mov dx, -3948
+mov al, [bx + si]
+mov bx, [bp + di]
+mov dx, [bp]
+mov ah, [bx + si + 4]
+mov al, [bx + si + 4999]
+mov [bx + di], cx
+mov [bp + si], cl
+mov [bp], ch
+mov ax, [bx + di - 37]
+mov [si - 300], cx
+mov dx, [bx - 32]
+mov [bp + di], byte 7
+mov [di + 901], word 347
+mov bp, [5]
+mov bx, [3458]
+mov ax, [2555]
+mov ax, [16]
+mov [2554], ax
+mov [15], ax
+
+push word [bp + si]
+push word [3000]
+push word [bx + di - 30]
+push cx
+push ax
+push dx
+push cs
+
+pop word [bp + si]
+pop word [3]
+pop word [bx + di - 3000]
+pop sp
+pop di
+pop si
+pop ds
+
+xchg ax, [bp - 1000]
+xchg [bx + 50], bp
+
+xchg ax, ax
+xchg ax, dx
+xchg ax, sp
+xchg ax, si
+xchg ax, di
+
+xchg cx, dx
+xchg si, cx
+xchg cl, ah
+
+in al, 200
+in al, dx
+in ax, dx
+
+out 44, ax
+out dx, al
+
+xlat
+lea ax, [bx + di + 1420]
+lea bx, [bp - 50]
+lea sp, [bp - 1003]
+lea di, [bx + si - 7]
+
+lds ax, [bx + di + 1420]
+lds bx, [bp - 50]
+lds sp, [bp - 1003]
+lds di, [bx + si - 7]
+
+les ax, [bx + di + 1420]
+les bx, [bp - 50]
+les sp, [bp - 1003]
+les di, [bx + si - 7]
+
+lahf
+sahf
+pushf
+popf
+
+add cx, [bp]
+add dx, [bx + si]
+add [bp + di + 5000], ah
+add [bx], al
+add sp, 392
+add si, 5
+add ax, 1000
+add ah, 30
+add al, 9
+add cx, bx
+add ch, al
+
+adc cx, [bp]
+adc dx, [bx + si]
+adc [bp + di + 5000], ah
+adc [bx], al
+adc sp, 392
+adc si, 5
+adc ax, 1000
+adc ah, 30
+adc al, 9
+adc cx, bx
+adc ch, al
+
+inc ax
+inc cx
+inc dh
+inc al
+inc ah
+inc sp
+inc di
+inc byte [bp + 1002]
+inc word [bx + 39]
+inc byte [bx + si + 5]
+inc word [bp + di - 10044]
+inc word [9349]
+inc byte [bp]
+
+aaa
+daa
+
+sub cx, [bp]
+sub dx, [bx + si]
+sub [bp + di + 5000], ah
+sub [bx], al
+sub sp, 392
+sub si, 5
+sub ax, 1000
+sub ah, 30
+sub al, 9
+sub cx, bx
+sub ch, al
+
+sbb cx, [bp]
+sbb dx, [bx + si]
+sbb [bp + di + 5000], ah
+sbb [bx], al
+sbb sp, 392
+sbb si, 5
+sbb ax, 1000
+sbb ah, 30
+sbb al, 9
+sbb cx, bx
+sbb ch, al
+
+dec ax
+dec cx
+dec dh
+dec al
+dec ah
+dec sp
+dec di
+dec byte [bp + 1002]
+dec word [bx + 39]
+dec byte [bx + si + 5]
+dec word [bp + di - 10044]
+dec word [9349]
+dec byte [bp]
+
+neg ax
+neg cx
+neg dh
+neg al
+neg ah
+neg sp
+neg di
+neg byte [bp + 1002]
+neg word [bx + 39]
+neg byte [bx + si + 5]
+neg word [bp + di - 10044]
+neg word [9349]
+neg byte [bp]
+
+cmp bx, cx
+cmp dh, [bp + 390]
+cmp [bp + 2], si
+cmp bl, 20
+cmp byte [bx], 34
+cmp ax, 23909
+
+aas
+das
+
+mul al
+mul cx
+mul word [bp]
+mul byte [bx + di + 500]
+
+imul ch
+imul dx
+imul byte [bx]
+imul word [9483]
+
+aam
+
+div bl
+div sp
+div byte [bx + si + 2990]
+div word [bp + di + 1000]
+
+idiv ax
+idiv si
+idiv byte [bp + si]
+idiv word [bx + 493]
+
+aad
+cbw
+cwd
+    
+not ah
+not bl
+not sp
+not si
+not word [bp]
+not byte [bp + 9905]
+
+shl ah, 1
+shr ax, 1
+sar bx, 1
+rol cx, 1
+ror dh, 1
+rcl sp, 1
+rcr bp, 1
+
+shl word [bp + 5], 1
+shr byte [bx + si - 199], 1
+sar byte [bx + di - 300], 1
+rol word [bp], 1
+ror word [4938], 1
+rcl byte [3], 1
+rcr word [bx], 1
+
+shl ah, cl
+shr ax, cl
+sar bx, cl
+rol cx, cl
+ror dh, cl
+rcl sp, cl
+rcr bp, cl
+
+shl word [bp + 5], cl
+shr word [bx + si - 199], cl
+sar byte [bx + di - 300], cl
+rol byte [bp], cl
+ror byte [4938], cl
+rcl byte [3], cl
+rcr word [bx], cl
+
+and al, ah
+and ch, cl
+and bp, si
+and di, sp
+and al, 93
+and ax, 20392
+and [bp + si + 10], ch
+and [bx + di + 1000], dx
+and bx, [bp]
+and cx, [4384]
+and byte [bp - 39], 239
+and word [bx + si - 4332], 10328
+
+test bx, cx
+test dh, [bp + 390]
+test [bp + 2], si
+test bl, 20
+test byte [bx], 34
+test ax, 23909
+
+or al, ah
+or ch, cl
+or bp, si
+or di, sp
+or al, 93
+or ax, 20392
+or [bp + si + 10], ch
+or [bx + di + 1000], dx
+or bx, [bp]
+or cx, [4384]
+or byte [bp - 39], 239
+or word [bx + si - 4332], 10328
+
+xor al, ah
+xor ch, cl
+xor bp, si
+xor di, sp
+xor al, 93
+xor ax, 20392
+xor [bp + si + 10], ch
+xor [bx + di + 1000], dx
+xor bx, [bp]
+xor cx, [4384]
+xor byte [bp - 39], 239
+xor word [bx + si - 4332], 10328
+
+rep movsb
+rep cmpsb
+rep scasb
+rep lodsb
+rep movsw
+rep cmpsw
+rep scasw
+rep lodsw
+
+; NOTE(casey): Special thanks (as always!) to Mārtiņš Možeiko for figuring out why NASM
+; wouldn't compile "rep stds" instructions. It was because it was a misprint in the 8086
+; manual! It was really just "rep stos", which of course is still in x64, and NASM
+; assembles it just fine.
+rep stosb
+rep stosw
+
+call [39201]
+call [bp - 100]
+call sp
+call ax
+
+jmp ax
+jmp di
+jmp [12]
+jmp [4395]
+    
+ret -7
+ret 500
+ret
+    
+label:
+je label
+jl label
+jle label
+jb label
+jbe label
+jp label
+jo label
+js label
+jne label
+jnl label
+jg label
+jnb label
+ja label
+jnp label
+jno label
+jns label
+loop label
+loopz label
+loopnz label
+jcxz label
+    
+int 13
+int3
+    
+into
+iret
+
+clc
+cmc
+stc
+cld
+std
+cli
+sti
+hlt
+wait
+
+lock not byte [bp + 9905]
+lock xchg [100], al
+
+mov al, cs:[bx + si]
+mov bx, ds:[bp + di]
+mov dx, es:[bp]
+mov ah, ss:[bx + si + 4]
+
+and ss:[bp + si + 10], ch
+or ds:[bx + di + 1000], dx
+xor bx, es:[bp]
+cmp cx, es:[4384]
+test byte cs:[bp - 39], 239
+sbb word cs:[bx + si - 4332], 10328
+
+lock not byte CS:[bp + 9905]
+
+;
+; NOTE(casey): These were not in the original homework set, but have been added since, as people
+; found instruction encodings that were not previously covered. Thank you to everyone who
+; submitted test cases!
+;
+
+call 123:456
+jmp 789:34
+
+mov [bx+si+59],es
+
+jmp 2620
+call 11804
+
+retf 17556
+ret 17560
+retf
+ret
+
+call [bp+si-0x3a]
+call far [bp+si-0x3a]
+jmp [di]
+jmp far [di]
+
+jmp 21862:30600
+
+;
+; TODO(casey): I would like to uncomment this, but as far as I can tell, NASM doesn't recognize the ESC instruction :(
+; so even if I just force the assembler to output the bits here, our disasm will fail to assemble because it will (correctly!)
+; print the esc instruction and NASM will error because it doesn't know what that is.
+;
+; esc 938,ax
+;
+
+;
+; TODO(casey): According to NASM, "rep movsb" is "not lockable". However the 8086 manual seems to think it is, and
+; even describes what happens when you you lock a rep: the lock is held for the duration of the rep operation. So...
+; yeah. Not sure why this doesn't work in NASM:
+;
+; lock rep movsb
+;
@@ -0,0 +1,27 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 43
+; ========================================================================
+
+bits 16
+
+mov ax, 1
+mov bx, 2
+mov cx, 3
+mov dx, 4
+
+mov sp, 5
+mov bp, 6
+mov si, 7
+mov di, 8
@@ -0,0 +1,23 @@
+--- test\listing_0043_immediate_movs execution ---
+mov ax, 1 ; ax:0x0->0x1 
+mov bx, 2 ; bx:0x0->0x2 
+mov cx, 3 ; cx:0x0->0x3 
+mov dx, 4 ; dx:0x0->0x4 
+mov sp, 5 ; sp:0x0->0x5 
+mov bp, 6 ; bp:0x0->0x6 
+mov si, 7 ; si:0x0->0x7 
+mov di, 8 ; di:0x0->0x8 
+
+Final registers:
+      ax: 0x0001 (1)
+      bx: 0x0002 (2)
+      cx: 0x0003 (3)
+      dx: 0x0004 (4)
+      sp: 0x0005 (5)
+      bp: 0x0006 (6)
+      si: 0x0007 (7)
+      di: 0x0008 (8)
+      es: 0x0000 (0)
+      ss: 0x0000 (0)
+      cs: 0x0000 (0)
+      ds: 0x0000 (0)
@@ -0,0 +1,32 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 44
+; ========================================================================
+
+bits 16
+
+mov ax, 1
+mov bx, 2
+mov cx, 3
+mov dx, 4
+
+mov sp, ax
+mov bp, bx
+mov si, cx
+mov di, dx
+
+mov dx, sp
+mov cx, bp
+mov bx, si
+mov ax, di
@@ -0,0 +1,27 @@
+--- test\listing_0044_register_movs execution ---
+mov ax, 1 ; ax:0x0->0x1 
+mov bx, 2 ; bx:0x0->0x2 
+mov cx, 3 ; cx:0x0->0x3 
+mov dx, 4 ; dx:0x0->0x4 
+mov sp, ax ; sp:0x0->0x1 
+mov bp, bx ; bp:0x0->0x2 
+mov si, cx ; si:0x0->0x3 
+mov di, dx ; di:0x0->0x4 
+mov dx, sp ; dx:0x4->0x1 
+mov cx, bp ; cx:0x3->0x2 
+mov bx, si ; bx:0x2->0x3 
+mov ax, di ; ax:0x1->0x4 
+
+Final registers:
+      ax: 0x0004 (4)
+      bx: 0x0003 (3)
+      cx: 0x0002 (2)
+      dx: 0x0001 (1)
+      sp: 0x0001 (1)
+      bp: 0x0002 (2)
+      si: 0x0003 (3)
+      di: 0x0004 (4)
+      es: 0x0000 (0)
+      ss: 0x0000 (0)
+      cs: 0x0000 (0)
+      ds: 0x0000 (0)
@@ -0,0 +1,43 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 45
+; ========================================================================
+
+bits 16
+
+mov ax, 0x2222
+mov bx, 0x4444
+mov cx, 0x6666
+mov dx, 0x8888
+
+mov ss, ax
+mov ds, bx
+mov es, cx
+
+mov al, 0x11
+mov bh, 0x33
+mov cl, 0x55
+mov dh, 0x77
+
+mov ah, bl
+mov cl, dh
+
+mov ss, ax
+mov ds, bx
+mov es, cx
+
+mov sp, ss
+mov bp, ds
+mov si, es
+mov di, dx
@@ -0,0 +1,35 @@
+--- test\listing_0045_challenge_register_movs execution ---
+mov ax, 8738 ; ax:0x0->0x2222 
+mov bx, 17476 ; bx:0x0->0x4444 
+mov cx, 26214 ; cx:0x0->0x6666 
+mov dx, 34952 ; dx:0x0->0x8888 
+mov ss, ax ; ss:0x0->0x2222 
+mov ds, bx ; ds:0x0->0x4444 
+mov es, cx ; es:0x0->0x6666 
+mov al, 17 ; ax:0x2222->0x2211 
+mov bh, 51 ; bx:0x4444->0x3344 
+mov cl, 85 ; cx:0x6666->0x6655 
+mov dh, 119 ; dx:0x8888->0x7788 
+mov ah, bl ; ax:0x2211->0x4411 
+mov cl, dh ; cx:0x6655->0x6677 
+mov ss, ax ; ss:0x2222->0x4411 
+mov ds, bx ; ds:0x4444->0x3344 
+mov es, cx ; es:0x6666->0x6677 
+mov sp, ss ; sp:0x0->0x4411 
+mov bp, ds ; bp:0x0->0x3344 
+mov si, es ; si:0x0->0x6677 
+mov di, dx ; di:0x0->0x7788 
+
+Final registers:
+      ax: 0x4411 (17425)
+      bx: 0x3344 (13124)
+      cx: 0x6677 (26231)
+      dx: 0x7788 (30600)
+      sp: 0x4411 (17425)
+      bp: 0x3344 (13124)
+      si: 0x6677 (26231)
+      di: 0x7788 (30600)
+      es: 0x6677 (26231)
+      ss: 0x4411 (17425)
+      cs: 0x0000 (0)
+      ds: 0x3344 (13124)
@@ -0,0 +1,28 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 46
+; ========================================================================
+
+bits 16
+
+mov bx, -4093
+mov cx, 3841
+sub bx, cx
+
+mov sp, 998
+mov bp, 999
+cmp bp, sp
+
+add bp, 1027
+sub bp, 2026
@@ -0,0 +1,24 @@
+--- test\listing_0046_add_sub_cmp execution ---
+mov bx, 61443 ; bx:0x0->0xf003 
+mov cx, 3841 ; cx:0x0->0xf01 
+sub bx, cx ; bx:0xf003->0xe102 flags:->S 
+mov sp, 998 ; sp:0x0->0x3e6 
+mov bp, 999 ; bp:0x0->0x3e7 
+cmp bp, sp ; flags:S-> 
+add bp, 1027 ; bp:0x3e7->0x7ea 
+sub bp, 2026 ; bp:0x7ea->0x0 flags:->PZ 
+
+Final registers:
+      bx: 0xe102 (57602)
+      cx: 0x0f01 (3841)
+      sp: 0x03e6 (998)
+      ax: 0x0000 (0)
+      bp: 0x0000 (0)
+      dx: 0x0000 (0)
+      si: 0x0000 (0)
+      di: 0x0000 (0)
+      es: 0x0000 (0)
+      ss: 0x0000 (0)
+      cs: 0x0000 (0)
+      ds: 0x0000 (0)
+   flags: PZ
@@ -0,0 +1,36 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 47
+; ========================================================================
+
+bits 16
+
+add bx, 30000
+add bx, 10000
+sub bx, 5000
+sub bx, 5000
+
+mov bx, 1
+mov cx, 100
+add bx, cx
+
+mov dx, 10
+sub cx, dx
+
+add bx, 40000
+add cx, -90
+
+mov sp, 99
+mov bp, 98
+cmp bp, sp
@@ -0,0 +1,22 @@
+--- test\listing_0047_challenge_flags execution ---
+add bx, 30000 ; bx:0x0->0x7530 flags:->P 
+add bx, 10000 ; bx:0x7530->0x9c40 flags:P->SO 
+sub bx, 5000 ; bx:0x9c40->0x88b8 flags:SO->PAS 
+sub bx, 5000 ; bx:0x88b8->0x7530 flags:PAS->PO 
+mov bx, 1 ; bx:0x7530->0x1 
+mov cx, 100 ; cx:0x0->0x64 
+add bx, cx ; bx:0x1->0x65 flags:PO->P 
+mov dx, 10 ; dx:0x0->0xa 
+sub cx, dx ; cx:0x64->0x5a flags:P->PA 
+add bx, 40000 ; bx:0x65->0x9ca5 flags:PA->PS 
+add cx, -90 ; cx:0x5a->0x0 flags:PS->CPAZ 
+mov sp, 99 ; sp:0x0->0x63 
+mov bp, 98 ; bp:0x0->0x62 
+cmp bp, sp ; flags:CPAZ->CPAS 
+
+Final registers:
+      bx: 0x9ca5 (40101)
+      dx: 0x000a (10)
+      sp: 0x0063 (99)
+      bp: 0x0062 (98)
+   flags: CPAS
@@ -0,0 +1,23 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 48
+; ========================================================================
+
+bits 16
+
+mov cx, 200
+mov bx, cx
+add cx, 1000
+mov bx, 2000
+sub cx, bx
@@ -0,0 +1,12 @@
+--- test\listing_0048_ip_register execution ---
+mov cx, 200 ; cx:0x0->0xc8 ip:0x0->0x3 
+mov bx, cx ; bx:0x0->0xc8 ip:0x3->0x5 
+add cx, 1000 ; cx:0xc8->0x4b0 ip:0x5->0x9 flags:->A 
+mov bx, 2000 ; bx:0xc8->0x7d0 ip:0x9->0xc 
+sub cx, bx ; cx:0x4b0->0xfce0 ip:0xc->0xe flags:A->CS 
+
+Final registers:
+      bx: 0x07d0 (2000)
+      cx: 0xfce0 (64736)
+      ip: 0x000e (14)
+   flags: CS
@@ -0,0 +1,24 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 49
+; ========================================================================
+
+bits 16
+
+mov cx, 3
+mov bx, 1000
+loop_start:
+add bx, 10
+sub cx, 1
+jnz loop_start
@@ -0,0 +1,17 @@
+--- test\listing_0049_conditional_jumps execution ---
+mov cx, 3 ; cx:0x0->0x3 ip:0x0->0x3 
+mov bx, 1000 ; bx:0x0->0x3e8 ip:0x3->0x6 
+add bx, 10 ; bx:0x3e8->0x3f2 ip:0x6->0x9 flags:->A 
+sub cx, 1 ; cx:0x3->0x2 ip:0x9->0xc flags:A-> 
+jne $-6 ; ip:0xc->0x6 
+add bx, 10 ; bx:0x3f2->0x3fc ip:0x6->0x9 flags:->P 
+sub cx, 1 ; cx:0x2->0x1 ip:0x9->0xc flags:P-> 
+jne $-6 ; ip:0xc->0x6 
+add bx, 10 ; bx:0x3fc->0x406 ip:0x6->0x9 flags:->PA 
+sub cx, 1 ; cx:0x1->0x0 ip:0x9->0xc flags:PA->PZ 
+jne $-6 ; ip:0xc->0xe 
+
+Final registers:
+      bx: 0x0406 (1030)
+      ip: 0x000e (14)
+   flags: PZ
@@ -0,0 +1,38 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 50
+; ========================================================================
+
+bits 16
+
+mov ax, 10
+mov bx, 10
+mov cx, 10
+
+label_0:
+cmp bx, cx
+je label_1
+
+add ax, 1
+jp label_2
+
+label_1:
+sub bx, 5
+jb label_3
+
+label_2:
+sub cx, 2
+
+label_3:
+loopnz label_0
@@ -0,0 +1,37 @@
+--- test\listing_0050_challenge_jumps execution ---
+mov ax, 10 ; ax:0x0->0xa ip:0x0->0x3 
+mov bx, 10 ; bx:0x0->0xa ip:0x3->0x6 
+mov cx, 10 ; cx:0x0->0xa ip:0x6->0x9 
+cmp bx, cx ; ip:0x9->0xb flags:->PZ 
+je $+7 ; ip:0xb->0x12 
+sub bx, 5 ; bx:0xa->0x5 ip:0x12->0x15 flags:PZ->P 
+jb $+5 ; ip:0x15->0x17 
+sub cx, 2 ; cx:0xa->0x8 ip:0x17->0x1a flags:P-> 
+loopnz $-17 ; cx:0x8->0x7 ip:0x1a->0x9 
+cmp bx, cx ; ip:0x9->0xb flags:->CAS 
+je $+7 ; ip:0xb->0xd 
+add ax, 1 ; ax:0xa->0xb ip:0xd->0x10 flags:CAS-> 
+jp $+7 ; ip:0x10->0x12 
+sub bx, 5 ; bx:0x5->0x0 ip:0x12->0x15 flags:->PZ 
+jb $+5 ; ip:0x15->0x17 
+sub cx, 2 ; cx:0x7->0x5 ip:0x17->0x1a flags:PZ->P 
+loopnz $-17 ; cx:0x5->0x4 ip:0x1a->0x9 
+cmp bx, cx ; ip:0x9->0xb flags:P->CPAS 
+je $+7 ; ip:0xb->0xd 
+add ax, 1 ; ax:0xb->0xc ip:0xd->0x10 flags:CPAS->P 
+jp $+7 ; ip:0x10->0x17 
+sub cx, 2 ; cx:0x4->0x2 ip:0x17->0x1a flags:P-> 
+loopnz $-17 ; cx:0x2->0x1 ip:0x1a->0x9 
+cmp bx, cx ; ip:0x9->0xb flags:->CPAS 
+je $+7 ; ip:0xb->0xd 
+add ax, 1 ; ax:0xc->0xd ip:0xd->0x10 flags:CPAS-> 
+jp $+7 ; ip:0x10->0x12 
+sub bx, 5 ; bx:0x0->0xfffb ip:0x12->0x15 flags:->CAS 
+jb $+5 ; ip:0x15->0x1a 
+loopnz $-17 ; cx:0x1->0x0 ip:0x1a->0x1c 
+
+Final registers:
+      ax: 0x000d (13)
+      bx: 0xfffb (65531)
+      ip: 0x001c (28)
+   flags: CAS
@@ -0,0 +1,30 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 51
+; ========================================================================
+
+bits 16
+
+mov word [1000], 1
+mov word [1002], 2
+mov word [1004], 3
+mov word [1006], 4
+
+mov bx, 1000
+mov word [bx + 4], 10
+
+mov bx, word [1000]
+mov cx, word [1002]
+mov dx, word [1004]
+mov bp, word [1006]
@@ -0,0 +1,18 @@
+--- test\listing_0051_memory_mov execution ---
+mov word [+1000], 1 ; ip:0x0->0x6 
+mov word [+1002], 2 ; ip:0x6->0xc 
+mov word [+1004], 3 ; ip:0xc->0x12 
+mov word [+1006], 4 ; ip:0x12->0x18 
+mov bx, 1000 ; bx:0x0->0x3e8 ip:0x18->0x1b 
+mov word [bx+4], 10 ; ip:0x1b->0x20 
+mov bx, [+1000] ; bx:0x3e8->0x1 ip:0x20->0x24 
+mov cx, [+1002] ; cx:0x0->0x2 ip:0x24->0x28 
+mov dx, [+1004] ; dx:0x0->0xa ip:0x28->0x2c 
+mov bp, [+1006] ; bp:0x0->0x4 ip:0x2c->0x30 
+
+Final registers:
+      bx: 0x0001 (1)
+      cx: 0x0002 (2)
+      dx: 0x000a (10)
+      bp: 0x0004 (4)
+      ip: 0x0030 (48)
@@ -0,0 +1,36 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 52
+; ========================================================================
+
+bits 16
+
+mov dx, 6
+mov bp, 1000
+
+mov si, 0
+init_loop_start:
+	mov word [bp + si], si
+	add si, 2
+	cmp si, dx
+	jnz init_loop_start
+
+mov bx, 0
+mov si, 0
+add_loop_start:
+	mov cx, word [bp + si]
+	add bx, cx
+	add si, 2
+	cmp si, dx
+	jnz add_loop_start
@@ -0,0 +1,42 @@
+--- test\listing_0052_memory_add_loop execution ---
+mov dx, 6 ; dx:0x0->0x6 ip:0x0->0x3 
+mov bp, 1000 ; bp:0x0->0x3e8 ip:0x3->0x6 
+mov si, 0 ; ip:0x6->0x9 
+mov word [bp+si], si ; ip:0x9->0xb 
+add si, 2 ; si:0x0->0x2 ip:0xb->0xe 
+cmp si, dx ; ip:0xe->0x10 flags:->CPAS 
+jne $-7 ; ip:0x10->0x9 
+mov word [bp+si], si ; ip:0x9->0xb 
+add si, 2 ; si:0x2->0x4 ip:0xb->0xe flags:CPAS-> 
+cmp si, dx ; ip:0xe->0x10 flags:->CAS 
+jne $-7 ; ip:0x10->0x9 
+mov word [bp+si], si ; ip:0x9->0xb 
+add si, 2 ; si:0x4->0x6 ip:0xb->0xe flags:CAS->P 
+cmp si, dx ; ip:0xe->0x10 flags:P->PZ 
+jne $-7 ; ip:0x10->0x12 
+mov bx, 0 ; ip:0x12->0x15 
+mov si, 0 ; si:0x6->0x0 ip:0x15->0x18 
+mov cx, [bp+si] ; ip:0x18->0x1a 
+add bx, cx ; ip:0x1a->0x1c 
+add si, 2 ; si:0x0->0x2 ip:0x1c->0x1f flags:PZ-> 
+cmp si, dx ; ip:0x1f->0x21 flags:->CPAS 
+jne $-9 ; ip:0x21->0x18 
+mov cx, [bp+si] ; cx:0x0->0x2 ip:0x18->0x1a 
+add bx, cx ; bx:0x0->0x2 ip:0x1a->0x1c flags:CPAS-> 
+add si, 2 ; si:0x2->0x4 ip:0x1c->0x1f 
+cmp si, dx ; ip:0x1f->0x21 flags:->CAS 
+jne $-9 ; ip:0x21->0x18 
+mov cx, [bp+si] ; cx:0x2->0x4 ip:0x18->0x1a 
+add bx, cx ; bx:0x2->0x6 ip:0x1a->0x1c flags:CAS->P 
+add si, 2 ; si:0x4->0x6 ip:0x1c->0x1f 
+cmp si, dx ; ip:0x1f->0x21 flags:P->PZ 
+jne $-9 ; ip:0x21->0x23 
+
+Final registers:
+      bx: 0x0006 (6)
+      cx: 0x0004 (4)
+      dx: 0x0006 (6)
+      bp: 0x03e8 (1000)
+      si: 0x0006 (6)
+      ip: 0x0023 (35)
+   flags: PZ
@@ -0,0 +1,35 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 53
+; ========================================================================
+
+bits 16
+
+mov dx, 6
+mov bp, 1000
+
+mov si, 0
+init_loop_start:
+	mov word [bp + si], si
+	add si, 2
+	cmp si, dx
+	jnz init_loop_start
+
+mov bx, 0
+mov si, dx
+sub bp, 2
+add_loop_start:
+	add bx, word [bp + si]
+	sub si, 2
+	jnz add_loop_start
@@ -0,0 +1,35 @@
+--- test\listing_0053_add_loop_challenge execution ---
+mov dx, 6 ; dx:0x0->0x6 ip:0x0->0x3 
+mov bp, 1000 ; bp:0x0->0x3e8 ip:0x3->0x6 
+mov si, 0 ; ip:0x6->0x9 
+mov word [bp+si], si ; ip:0x9->0xb 
+add si, 2 ; si:0x0->0x2 ip:0xb->0xe 
+cmp si, dx ; ip:0xe->0x10 flags:->CPAS 
+jne $-7 ; ip:0x10->0x9 
+mov word [bp+si], si ; ip:0x9->0xb 
+add si, 2 ; si:0x2->0x4 ip:0xb->0xe flags:CPAS-> 
+cmp si, dx ; ip:0xe->0x10 flags:->CAS 
+jne $-7 ; ip:0x10->0x9 
+mov word [bp+si], si ; ip:0x9->0xb 
+add si, 2 ; si:0x4->0x6 ip:0xb->0xe flags:CAS->P 
+cmp si, dx ; ip:0xe->0x10 flags:P->PZ 
+jne $-7 ; ip:0x10->0x12 
+mov bx, 0 ; ip:0x12->0x15 
+mov si, dx ; ip:0x15->0x17 
+sub bp, 2 ; bp:0x3e8->0x3e6 ip:0x17->0x1a flags:PZ-> 
+add bx, [bp+si] ; bx:0x0->0x4 ip:0x1a->0x1c 
+sub si, 2 ; si:0x6->0x4 ip:0x1c->0x1f 
+jne $-5 ; ip:0x1f->0x1a 
+add bx, [bp+si] ; bx:0x4->0x6 ip:0x1a->0x1c flags:->P 
+sub si, 2 ; si:0x4->0x2 ip:0x1c->0x1f flags:P-> 
+jne $-5 ; ip:0x1f->0x1a 
+add bx, [bp+si] ; ip:0x1a->0x1c flags:->P 
+sub si, 2 ; si:0x2->0x0 ip:0x1c->0x1f flags:P->PZ 
+jne $-5 ; ip:0x1f->0x21 
+
+Final registers:
+      bx: 0x0006 (6)
+      dx: 0x0006 (6)
+      bp: 0x03e6 (998)
+      ip: 0x0021 (33)
+   flags: PZ
@@ -0,0 +1,43 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 54
+; ========================================================================
+
+bits 16
+
+; Start image after one row, to avoid overwriting our code!
+mov bp, 64*4
+
+mov dx, 0
+y_loop_start:
+	
+	mov cx, 0
+	x_loop_start:
+		; Fill pixel
+		mov word [bp + 0], cx ; Red
+		mov word [bp + 2], dx ; Blue
+		mov byte [bp + 3], 255 ; Alpha
+			
+		; Advance pixel location
+		add bp, 4
+			
+		; Advance X coordinate and loop
+		add cx, 1
+		cmp cx, 64
+		jnz x_loop_start
+	
+	; Advance Y coordinate and loop
+	add dx, 1
+	cmp dx, 64
+	jnz y_loop_start
@@ -0,0 +1,53 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 55
+; ========================================================================
+
+bits 16
+
+; Start image after one row, to avoid overwriting our code!
+mov bp, 64*4
+
+; Draw the solid rectangle red/blue/alpha
+mov dx, 64
+y_loop_start:
+	
+	mov cx, 64
+	x_loop_start:
+		mov byte [bp + 0], cl  ; Red
+		mov byte [bp + 1], 0   ; Green
+		mov byte [bp + 2], dl  ; Blue
+		mov byte [bp + 3], 255 ; Alpha
+		add bp, 4
+			
+		loop x_loop_start
+	
+	sub dx, 1
+	jnz y_loop_start
+
+; Add the line rectangle green
+mov bp, 64*4 + 4*64 + 4
+mov bx, bp
+mov cx, 62
+outline_loop_start:
+	
+	mov byte [bp + 1], 255 ; Top line
+	mov byte [bp + 61*64*4 + 1], 255 ; Bottom line
+	mov byte [bx + 1], 255 ; Left line
+	mov byte [bx + 61*4 + 1], 255 ; Right  line
+	
+	add bp, 4
+	add bx, 4*64
+			
+	loop outline_loop_start
@@ -0,0 +1,41 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 56
+; ========================================================================
+
+bits 16
+
+mov bx, 1000
+mov bp, 2000
+mov si, 3000
+mov di, 4000
+
+mov cx, bx
+mov dx, 12
+
+mov dx, [1000]
+
+mov cx, [bx]
+mov cx, [bp]
+mov [si], cx
+mov [di], cx 
+
+mov cx, [bx + 1000]
+mov cx, [bp + 1000]
+mov [si + 1000], cx 
+mov [di + 1000], cx
+
+add cx, dx
+add [di + 1000], cx
+add dx, 50
@@ -0,0 +1,72 @@
+**************
+**** 8086 ****
+**************
+
+WARNING: Clocks reported by this utility are strictly from the 8086 manual.
+They will be inaccurate, both because the manual clocks are estimates, and because
+some of the entries in the manual look highly suspicious and are probably typos.
+
+--- test\listing_0056_estimating_cycles execution ---
+mov bx, 1000 ; Clocks: +4 = 4 | bx:0x0->0x3e8 ip:0x0->0x3 
+mov bp, 2000 ; Clocks: +4 = 8 | bp:0x0->0x7d0 ip:0x3->0x6 
+mov si, 3000 ; Clocks: +4 = 12 | si:0x0->0xbb8 ip:0x6->0x9 
+mov di, 4000 ; Clocks: +4 = 16 | di:0x0->0xfa0 ip:0x9->0xc 
+mov cx, bx ; Clocks: +2 = 18 | cx:0x0->0x3e8 ip:0xc->0xe 
+mov dx, 12 ; Clocks: +4 = 22 | dx:0x0->0xc ip:0xe->0x11 
+mov dx, [+1000] ; Clocks: +14 = 36 (8 + 6ea) | dx:0xc->0x0 ip:0x11->0x15 
+mov cx, [bx] ; Clocks: +13 = 49 (8 + 5ea) | cx:0x3e8->0x0 ip:0x15->0x17 
+mov cx, [bp] ; Clocks: +13 = 62 (8 + 5ea) | ip:0x17->0x1a 
+mov word [si], cx ; Clocks: +14 = 76 (9 + 5ea) | ip:0x1a->0x1c 
+mov word [di], cx ; Clocks: +14 = 90 (9 + 5ea) | ip:0x1c->0x1e 
+mov cx, [bx+1000] ; Clocks: +17 = 107 (8 + 9ea) | ip:0x1e->0x22 
+mov cx, [bp+1000] ; Clocks: +17 = 124 (8 + 9ea) | ip:0x22->0x26 
+mov word [si+1000], cx ; Clocks: +18 = 142 (9 + 9ea) | ip:0x26->0x2a 
+mov word [di+1000], cx ; Clocks: +18 = 160 (9 + 9ea) | ip:0x2a->0x2e 
+add cx, dx ; Clocks: +3 = 163 | ip:0x2e->0x30 flags:->PZ 
+add word [di+1000], cx ; Clocks: +25 = 188 (16 + 9ea) | ip:0x30->0x34 
+add dx, 50 ; Clocks: +4 = 192 | dx:0x0->0x32 ip:0x34->0x37 flags:PZ-> 
+
+Final registers:
+      bx: 0x03e8 (1000)
+      dx: 0x0032 (50)
+      bp: 0x07d0 (2000)
+      si: 0x0bb8 (3000)
+      di: 0x0fa0 (4000)
+      ip: 0x0037 (55)
+
+
+**************
+**** 8088 ****
+**************
+
+WARNING: Clocks reported by this utility are strictly from the 8086 manual.
+They will be inaccurate, both because the manual clocks are estimates, and because
+some of the entries in the manual look highly suspicious and are probably typos.
+
+--- test\listing_0056_estimating_cycles execution ---
+mov bx, 1000 ; Clocks: +4 = 4 | bx:0x0->0x3e8 ip:0x0->0x3
+mov bp, 2000 ; Clocks: +4 = 8 | bp:0x0->0x7d0 ip:0x3->0x6
+mov si, 3000 ; Clocks: +4 = 12 | si:0x0->0xbb8 ip:0x6->0x9
+mov di, 4000 ; Clocks: +4 = 16 | di:0x0->0xfa0 ip:0x9->0xc
+mov cx, bx ; Clocks: +2 = 18 | cx:0x0->0x3e8 ip:0xc->0xe
+mov dx, 12 ; Clocks: +4 = 22 | dx:0x0->0xc ip:0xe->0x11
+mov dx, [+1000] ; Clocks: +18 = 40 (8 + 6ea + 4p) | dx:0xc->0x0 ip:0x11->0x15
+mov cx, [bx] ; Clocks: +17 = 57 (8 + 5ea + 4p) | cx:0x3e8->0x0 ip:0x15->0x17
+mov cx, [bp] ; Clocks: +17 = 74 (8 + 5ea + 4p) | ip:0x17->0x1a
+mov word [si], cx ; Clocks: +18 = 92 (9 + 5ea + 4p) | ip:0x1a->0x1c
+mov word [di], cx ; Clocks: +18 = 110 (9 + 5ea + 4p) | ip:0x1c->0x1e
+mov cx, [bx+1000] ; Clocks: +21 = 131 (8 + 9ea + 4p) | ip:0x1e->0x22
+mov cx, [bp+1000] ; Clocks: +21 = 152 (8 + 9ea + 4p) | ip:0x22->0x26
+mov word [si+1000], cx ; Clocks: +22 = 174 (9 + 9ea + 4p) | ip:0x26->0x2a
+mov word [di+1000], cx ; Clocks: +22 = 196 (9 + 9ea + 4p) | ip:0x2a->0x2e
+add cx, dx ; Clocks: +3 = 199 | ip:0x2e->0x30 flags:->PZ
+add word [di+1000], cx ; Clocks: +33 = 232 (16 + 9ea + 8p) | ip:0x30->0x34
+add dx, 50 ; Clocks: +4 = 236 | dx:0x0->0x32 ip:0x34->0x37 flags:PZ->
+
+Final registers:
+      bx: 0x03e8 (1000)
+      dx: 0x0032 (50)
+      bp: 0x07d0 (2000)
+      si: 0x0bb8 (3000)
+      di: 0x0fa0 (4000)
+      ip: 0x0037 (55)
@@ -0,0 +1,42 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 57
+; ========================================================================
+
+bits 16
+
+mov bx, 1000
+mov bp, 2000
+mov si, 3000
+mov di, 4000
+
+mov cx, [bp + di]
+mov [bx + si], cx
+
+mov cx, [bp + si]
+mov [bx + di], cx
+
+mov cx, [bp + di + 1000]
+mov [bx + si + 1000], cx
+
+mov cx, [bp + si + 1000]
+mov [bx + di + 1000], cx
+
+add dx, [bp + si + 1000]
+
+add word [bp + si], 76
+
+add dx, [bp + si + 1001]
+add [di + 999], dx
+add word [bp + si], 75
@@ -0,0 +1,71 @@
+**************
+**** 8086 ****
+**************
+
+WARNING: Clocks reported by this utility are strictly from the 8086 manual.
+They will be inaccurate, both because the manual clocks are estimates, and because
+some of the entries in the manual look highly suspicious and are probably typos.
+
+--- test\listing_0057_challenge_cycles execution ---
+mov bx, 1000 ; Clocks: +4 = 4 | bx:0x0->0x3e8 ip:0x0->0x3 
+mov bp, 2000 ; Clocks: +4 = 8 | bp:0x0->0x7d0 ip:0x3->0x6 
+mov si, 3000 ; Clocks: +4 = 12 | si:0x0->0xbb8 ip:0x6->0x9 
+mov di, 4000 ; Clocks: +4 = 16 | di:0x0->0xfa0 ip:0x9->0xc 
+mov cx, [bp+di] ; Clocks: +15 = 31 (8 + 7ea) | ip:0xc->0xe 
+mov word [bx+si], cx ; Clocks: +16 = 47 (9 + 7ea) | ip:0xe->0x10 
+mov cx, [bp+si] ; Clocks: +16 = 63 (8 + 8ea) | ip:0x10->0x12 
+mov word [bx+di], cx ; Clocks: +17 = 80 (9 + 8ea) | ip:0x12->0x14 
+mov cx, [bp+di+1000] ; Clocks: +19 = 99 (8 + 11ea) | ip:0x14->0x18 
+mov word [bx+si+1000], cx ; Clocks: +20 = 119 (9 + 11ea) | ip:0x18->0x1c 
+mov cx, [bp+si+1000] ; Clocks: +20 = 139 (8 + 12ea) | ip:0x1c->0x20 
+mov word [bx+di+1000], cx ; Clocks: +21 = 160 (9 + 12ea) | ip:0x20->0x24 
+add dx, [bp+si+1000] ; Clocks: +21 = 181 (9 + 12ea) | ip:0x24->0x28 flags:->PZ 
+add word [bp+si], 76 ; Clocks: +25 = 206 (17 + 8ea) | ip:0x28->0x2b flags:PZ-> 
+add dx, [bp+si+1001] ; Clocks: +25 = 231 (9 + 12ea + 4p) | ip:0x2b->0x2f flags:->PZ 
+add word [di+999], dx ; Clocks: +33 = 264 (16 + 9ea + 8p) | ip:0x2f->0x33 flags:PZ->P 
+add word [bp+si], 75 ; Clocks: +25 = 289 (17 + 8ea) | ip:0x33->0x36 flags:P->A 
+
+Final registers:
+      bx: 0x03e8 (1000)
+      bp: 0x07d0 (2000)
+      si: 0x0bb8 (3000)
+      di: 0x0fa0 (4000)
+      ip: 0x0036 (54)
+   flags: A
+
+
+
+**************
+**** 8088 ****
+**************
+
+WARNING: Clocks reported by this utility are strictly from the 8086 manual.
+They will be inaccurate, both because the manual clocks are estimates, and because
+some of the entries in the manual look highly suspicious and are probably typos.
+
+--- test\listing_0057_challenge_cycles execution ---
+mov bx, 1000 ; Clocks: +4 = 4 | bx:0x0->0x3e8 ip:0x0->0x3
+mov bp, 2000 ; Clocks: +4 = 8 | bp:0x0->0x7d0 ip:0x3->0x6
+mov si, 3000 ; Clocks: +4 = 12 | si:0x0->0xbb8 ip:0x6->0x9
+mov di, 4000 ; Clocks: +4 = 16 | di:0x0->0xfa0 ip:0x9->0xc
+mov cx, [bp+di] ; Clocks: +19 = 35 (8 + 7ea + 4p) | ip:0xc->0xe
+mov word [bx+si], cx ; Clocks: +20 = 55 (9 + 7ea + 4p) | ip:0xe->0x10
+mov cx, [bp+si] ; Clocks: +20 = 75 (8 + 8ea + 4p) | ip:0x10->0x12
+mov word [bx+di], cx ; Clocks: +21 = 96 (9 + 8ea + 4p) | ip:0x12->0x14
+mov cx, [bp+di+1000] ; Clocks: +23 = 119 (8 + 11ea + 4p) | ip:0x14->0x18
+mov word [bx+si+1000], cx ; Clocks: +24 = 143 (9 + 11ea + 4p) | ip:0x18->0x1c
+mov cx, [bp+si+1000] ; Clocks: +24 = 167 (8 + 12ea + 4p) | ip:0x1c->0x20
+mov word [bx+di+1000], cx ; Clocks: +25 = 192 (9 + 12ea + 4p) | ip:0x20->0x24
+add dx, [bp+si+1000] ; Clocks: +25 = 217 (9 + 12ea + 4p) | ip:0x24->0x28 flags:->PZ
+add word [bp+si], 76 ; Clocks: +33 = 250 (17 + 8ea + 8p) | ip:0x28->0x2b flags:PZ->
+add dx, [bp+si+1001] ; Clocks: +25 = 275 (9 + 12ea + 4p) | ip:0x2b->0x2f flags:->PZ
+add word [di+999], dx ; Clocks: +33 = 308 (16 + 9ea + 8p) | ip:0x2f->0x33 flags:PZ->P
+add word [bp+si], 75 ; Clocks: +33 = 341 (17 + 8ea + 8p) | ip:0x33->0x36 flags:P->A
+
+Final registers:
+      bx: 0x03e8 (1000)
+      bp: 0x07d0 (2000)
+      si: 0x0bb8 (3000)
+      di: 0x0fa0 (4000)
+      ip: 0x0036 (54)
+   flags: A
@@ -1,335 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/stat.h>
-#include <string.h>
-#include <assert.h>
-#include "lib.h"
-#include "decode.h"
-
-/// Get Effective Address Calculation Registers
-char* get_eac_register(char rm)
-{
-    char* reg_name;
-    switch (rm)
-    {
-    case 0b000: reg_name = "bx + si"; break;
-    case 0b001: reg_name = "bx + di"; break;
-    case 0b010: reg_name = "bp + si"; break;
-    case 0b011: reg_name = "bp + di"; break;
-    case 0b100: reg_name = "si";      break;
-    case 0b101: reg_name = "di";      break;
-    case 0b110: reg_name = "bp";      break;
-    case 0b111: reg_name = "bx";      break;
-    default: perror("Invalid R/M value"); exit(1);
-    }
-    return reg_name;
-}
-
-static char* reg_name(Register reg, char wide)
-{
-    return wide == 1 ? reg.fullname : reg.bytename;
-}
-
-static u8 mask_and_shift(u8 value, u8 mask)
-{
-    value &= mask;
-    int count = 0;
-    while ((mask & 0x1) == 0 && count < 8)
-    {
-        value >>= 1;
-        mask >>= 1;
-        count++;
-    }
-    return value;
-}
-
-ParsedInstruction parse_instruction(u8* buf)
-{
-    u8 inst = buf[0];
-    InstFormat fmt;
-    bool matched_inst = false;
-    // TODO: This might be a good time to learn how to make a hashtable in C
-    for (u16 i = 0; i < sizeof(inst_formats) / sizeof(InstFormat); i++)
-    {
-        if ((inst & ~inst_formats[i].mask_inst) == inst_formats[i].inst_enc)
-        {
-            fmt = inst_formats[i];
-            matched_inst = true;
-            break;
-        }
-    }
-    if (!matched_inst)
-        return (ParsedInstruction){.bytes_read = 0};
-    u8_opt d_opt = none_u8();
-    u8_opt s_opt = none_u8();
-    u8_opt w_opt = none_u8();
-    u8_opt reg_opt = none_u8();
-    u8_opt mod_opt = none_u8();
-    u8_opt rm_opt = none_u8();
-    u16_opt data_opt = none_u16();
-    u16_opt displacement_opt = none_u16();
-    u8 is_data_addr = false;
-
-    u16 bytes_read = 1;
-    bytes_read += fmt.has_operands ? 1 : 0;
-
-    if (fmt.has_d) d_opt = some_u8((inst & 0x2) >> 1);
-    if (fmt.has_s) s_opt = some_u8((inst & 0x2) >> 1);
-    if (fmt.has_rm) rm_opt = some_u8(buf[1] & 0x7);
-    if (fmt.has_mod) mod_opt = some_u8((buf[1] & 0b11000000) >> 6);
-    if (fmt.has_w) w_opt = some_u8(mask_and_shift(buf[0], fmt.mask_w));
-    if (fmt.parse_reg.tag == P_REG_MASK)
-    {
-        u8 reg = fmt.has_operands ? buf[1] : buf[0];
-        reg_opt = some_u8(mask_and_shift(reg, fmt.parse_reg.mask));
-    }
-    else if (fmt.parse_reg.tag == P_REG_FIXED)
-    {
-        reg_opt = some_u8(fmt.parse_reg.fixed);
-        is_data_addr = true;
-    }
-    if (fmt.has_data)
-    {
-        u8 idx = 1;
-        if (fmt.has_operands) idx += 1;
-        // This is a trick because mod == 1 and mod == 2 will displace one and two bytes
-        // respectively but mod == 3 wraps to 0 since it doesn't displace
-        if (fmt.has_displacement) idx += mod_opt.value % 3;
-        u16 data;
-        if (fmt.has_s && s_opt.value == 1)
-        {
-            data = (sbyte)buf[idx];
-            bytes_read += 1;
-        }
-        else
-        {
-            data = w_opt.value != 0 ? (i16)buf[idx+1] << 8 | buf[idx] : (sbyte)buf[idx];
-            bytes_read += w_opt.value == 0 ? 1 : 2;
-        }
-        data_opt = some_u16(data);
-    }
-    if (fmt.has_displacement && mod_opt.value % 3 > 0)
-    {
-        u16 disp = mod_opt.value == MODE_MEM_DIS_16
-            ? (i16)buf[3] << 8 | buf[2]
-            : (sbyte)buf[2];
-        displacement_opt = some_u16(disp);
-        bytes_read += mod_opt.value % 3;
-    }
-    else if (fmt.has_displacement && mod_opt.value == MODE_MEM_NO_DIS && rm_opt.value == 0x6)
-    {
-        displacement_opt = some_u16((i16)buf[3] << 8 | buf[2]);
-        bytes_read += 2;
-    }
-
-    return (ParsedInstruction) {
-        .id = fmt.id,
-        .name = fmt.name,
-        .data = data_opt,
-        .displacement = displacement_opt,
-        .w = w_opt,
-        .d = d_opt,
-        .s = s_opt,
-        .mod = mod_opt,
-        .reg = reg_opt,
-        .rm = rm_opt,
-        .is_data_addr = is_data_addr,
-        .bytes_read = bytes_read,
-    };
-}
-
-Instruction decode_instruction(ParsedInstruction inst)
-{
-    Operand opr1 , opr2 = {0};
-    i16 payload = 0;
-
-    IF_LET_SOME(u8, mod, inst.mod)
-    {
-        IF_LET_SOME(u8, reg, inst.reg)
-        {
-            opr1.tag = OPR_T_REGISTER;
-            opr1.reg.value = registers[(size_t)reg];
-            opr1.reg.wide = inst.w.value;
-        }
-        else
-        {
-            opr1.tag = OPR_T_IMMEDIATE;
-            opr1.imm.value = inst.data.value;
-            // TODO: This is dumb, we shouldn't do it this way
-            if (inst.s.value == 1) opr1.imm.direct = 0;
-            else opr1.imm.direct = inst.w.value + 1;
-        }
-        if (mod == MODE_RGSTR_MODE)
-        {
-            opr2.tag = OPR_T_REGISTER;
-            opr2.reg.value = registers[(size_t)inst.rm.value];
-            opr2.reg.wide = inst.w.value;
-        }
-        else if (mod == MODE_MEM_NO_DIS && inst.rm.value == 0x6)
-        {
-            opr2.tag = OPR_T_DIRADDR;
-            opr2.dir_addr.value = inst.displacement.value;
-        }
-        else
-        {
-            opr2.tag = OPR_T_MEMORY;
-            opr2.mem.eac_name = get_eac_register(inst.rm.value);
-            opr2.mem.mode = mod;
-            opr2.mem.displacement = (i16)inst.displacement.value;
-        }
-    }
-    else
-    {
-        IF_LET_SOME(u16, data, inst.data)
-        {
-            if (inst.is_data_addr)
-            {
-                opr1.tag = OPR_T_DIRADDR;
-                opr1.dir_addr.value = (i16)data;
-            }
-            else
-            {
-                opr1.tag = OPR_T_IMMEDIATE;
-                opr1.imm.value = (i16)data;
-                opr1.imm.direct = 0;
-            }
-        }
-        IF_LET_SOME(u8, reg, inst.reg)
-        {
-            opr2.tag = OPR_T_REGISTER;
-            opr2.reg.value = registers[(size_t)reg];
-            opr2.reg.wide = inst.w.value;
-        }
-    }
-    if (inst.d.tag == SOME && inst.d.value == 1)
-    {
-        Operand temp = opr1;
-        opr1 = opr2;
-        opr2 = temp;
-    }
-    return (Instruction) {
-        .id = inst.id,
-        .data = payload,
-        .operation = inst.name,
-        .src_opr = opr1,
-        .dst_opr = opr2,
-    };
-}
-
-void get_operand_string(char* str_buf, Operand oprnd)
-{
-    if (oprnd.tag == OPR_T_REGISTER)
-    {
-        strcpy(str_buf, reg_name(oprnd.reg.value, oprnd.reg.wide));
-    }
-    else if (oprnd.tag == OPR_T_MEMORY)
-    {
-        char disp_str[16] = {'\0'};
-        i16 disp = oprnd.mem.displacement;
-        if (disp != 0)
-            sprintf(disp_str, " %s %d", (disp > 0 ? "+" : "-"), abs(disp));
-        sprintf(str_buf, "[%s%s]", oprnd.mem.eac_name, disp_str);
-    }
-    else if (oprnd.tag == OPR_T_IMMEDIATE)
-    {
-        char *size = "";
-        if (oprnd.imm.direct > 0)
-            size = oprnd.imm.direct == 1 ? "byte " : "word ";
-        sprintf(str_buf, "%s%d", size, oprnd.imm.value);
-    }
-    else if (oprnd.tag == OPR_T_DIRADDR)
-    {
-        sprintf(str_buf, "[%d]", oprnd.dir_addr.value);
-    }
-}
-
-void get_instr_string(char* str_buf, Instruction inst)
-{
-    char src_str[32], dst_str[32];
-    get_operand_string(src_str, inst.src_opr);
-    get_operand_string(dst_str, inst.dst_opr);
-    sprintf(str_buf, "%s %s, %s", inst.operation, dst_str, src_str);
-}
-
-char *memory[65536];
-// Keep this global for debugging purposes
-u16 inst_count = 1;
-
-int main(int argc, char** argv)
-{
-    if (argc < 2)
-    {
-        printf("Usage: Please provide assembled instructions as input\n");
-        exit(0);
-    }
-
-    struct stat st;
-    if (stat(argv[1], &st) == -1)
-    {
-        perror("Unable to get file size\n");
-        return EXIT_FAILURE;
-    }
-
-    unsigned char* buffer = malloc(st.st_size);
-    if (!buffer)
-    {
-        perror("Unable to allocate memory for binary file");
-        return EXIT_FAILURE;
-    }
-
-    FILE *f = fopen(argv[1], "r");
-    if (!f)
-    {
-        perror("fopen\n");
-        free(buffer);
-        return EXIT_FAILURE;
-    }
-
-    size_t bytes_read = fread(buffer, sizeof(unsigned char), st.st_size, f);
-    if (bytes_read != (size_t)st.st_size)
-    {
-        fprintf(stderr, "Read of binary file to memory incomplete.\n");
-        free(buffer);
-        fclose(f);
-        return EXIT_FAILURE;
-    }
-
-    fclose(f);
-
-    printf("; Decoded 8086 Assembly Instructions\n\n");
-    printf("bits 16\n\n");
-
-    char *inst_str_buf = malloc(sizeof(char) * 256);
-    u32 bytes_processed = 0;
-    while (bytes_processed < bytes_read)
-    {
-        ParsedInstruction parsed = parse_instruction(buffer + bytes_processed);
-
-        if (parsed.bytes_read > 0)
-        {
-            Instruction inst = decode_instruction(parsed);
-            get_instr_string(inst_str_buf, inst);
-            bytes_processed += parsed.bytes_read;
-            // printf("%s %d/%ld", inst_str_buf, bytes_processed, bytes_read);
-            printf("%s", inst_str_buf);
-            int len = strlen(inst_str_buf);
-            for (int i = 0; i < 32 - len; i++)
-                printf(" ");
-            printf("; %d, %d", inst_count++, inst.id);
-        }
-        else
-        {
-            bytes_processed += 1;
-            fprintf(stderr, "___Unrecognized Instruction___");
-        }
-        // char inst = buffer[0];
-        // if (mov_inst(f, buffer, inst)) goto handled;
-        // if (add_inst(f, buffer, inst)) goto handled;
-    // handled:
-        printf("\n");
-    }
-    free(inst_str_buf);
-    free(buffer);
-
-    return 0;
-}
@@ -1,152 +0,0 @@
-#include "lib.h"
-
-enum Mode
-{
-    MODE_MEM_NO_DIS = 0b00,
-    MODE_MEM_DIS_08 = 0b01,
-    MODE_MEM_DIS_16 = 0b10,
-    MODE_RGSTR_MODE = 0b11,
-};
-
-typedef struct Register
-{
-    char* fullname;
-    char* bytename;
-    union {
-        struct {
-            char low;
-            char high;
-        };
-        u16 full;
-    } value;
-    u8 code;
-} Register;
-
-Register registers[8] = {
-    {.code = 0b000, .fullname = "ax", .bytename = "al"},
-    {.code = 0b001, .fullname = "cx", .bytename = "cl"},
-    {.code = 0b010, .fullname = "dx", .bytename = "dl"},
-    {.code = 0b011, .fullname = "bx", .bytename = "bl"},
-    {.code = 0b100, .fullname = "sp", .bytename = "ah"},
-    {.code = 0b101, .fullname = "bp", .bytename = "ch"},
-    {.code = 0b110, .fullname = "si", .bytename = "dh"},
-    {.code = 0b111, .fullname = "di", .bytename = "bh"},
-};
-
-enum OperandType {OPR_T_MEMORY, OPR_T_REGISTER, OPR_T_IMMEDIATE, OPR_T_DIRADDR};
-
-typedef struct Operand
-{
-    enum OperandType tag;
-    union {
-        struct Mem {
-            char *eac_name;
-            i16 displacement;
-            u8 mode;
-        } mem;
-        struct Reg {
-            Register value;
-            bool wide;
-        } reg;
-        struct Imm {
-            i16 value;
-            u8 direct;
-        } imm;
-        struct DirAddr {
-            i16 value;
-        } dir_addr;
-    };
-} Operand;
-
-enum ParseRegType { P_REG_NONE, P_REG_MASK, P_REG_FIXED };
-typedef struct ParseReg
-{
-    enum ParseRegType tag;
-    union {
-        u8 none;
-        u8 mask;
-        u8 fixed;
-    };
-} ParseReg;
-
-typedef struct InstFormat
-{
-    u16 id;
-    char *name;
-    ParseReg parse_reg;
-    u8 inst_enc;
-    u8 mask_inst;
-    u8 mask_w;
-    bool has_operands;
-    bool has_displacement;
-    bool has_data;
-    bool has_d;
-    bool has_w;
-    bool has_mod;
-    bool has_rm;
-    bool has_s;
-    bool has_SR;
-} InstFormat;
-
-typedef struct ParsedInstruction
-{
-    u16 id;
-    char *name;
-    u16_opt data;
-    u16_opt displacement;
-    u8_opt w;
-    u8_opt d;
-    u8_opt s;
-    u8_opt mod;
-    u8_opt reg;
-    u8_opt rm;
-    u8_opt SR;
-    u8 is_data_addr;
-    u8 bytes_read;
-} ParsedInstruction;
-
-typedef struct Instruction
-{
-    Operand src_opr;
-    Operand dst_opr;
-    i16 data;
-    char *operation;
-    u16 id;
-} Instruction;
-
-InstFormat inst_formats[] =
-{
-    ////////
-    // MOV
-    ////////
-    // Register/memory to/from register
-    {.id=1, .name="mov", .inst_enc=0b10001000, .mask_inst=0x3, .mask_w=0x1,
-     .has_operands=true, .has_displacement=true, .has_d=true, .has_w=true,
-     .has_mod=true, .has_rm=true, .parse_reg={.tag = P_REG_MASK, .mask=0b00111000} },
-    // Immediate to register/memory
-    {.id=2, .name="mov", .inst_enc=0b11000110, .mask_inst=0x1, .mask_w=0x1, .has_operands=true,
-     .has_displacement=true, .has_data=true, .has_w=true, .has_mod=true, .has_rm=true},
-    // Immediate to register
-    {.id=3, .name="mov", .inst_enc=0b10110000, .mask_inst=0xF, .mask_w=0x8,
-     .parse_reg={.tag = P_REG_MASK, .mask=0b00000111}, .has_data=true, .has_w=true},
-    // Memory to accumulator | Accumulator to memory using the `d` bit
-    // even though the manual doesn't specify it
-    {.id=4, .name="mov", .inst_enc=0b10100000, .mask_inst=0x3, .mask_w=0x1, .has_data=true,
-     .has_w=true, .has_d=true, .parse_reg={.tag = P_REG_FIXED, .fixed=0x0}},
-    // Register/memory to segment register and inverse using the `d` bit
-    {.id=5, .name="mov", .inst_enc=0b10001100, .mask_inst=0x3, .has_SR=true, .has_d=true,
-     .has_displacement=true, .has_mod=true, .has_rm=true},
-    ////////
-    // ADD
-    ////////
-    // Reg/memory with register or either
-    {.id=6, .name="add", .inst_enc=0b00000000, .mask_inst=0x3, .has_displacement=true,
-      .mask_w=0x1, .has_operands=true, .has_w=true, .has_d=true, .has_mod=true,
-      .has_rm=true, .parse_reg={.tag = P_REG_MASK, .mask=0b00111000}},
-    // Immediate to register/memory
-    {.id=7, .name="add", .inst_enc=0b10000000, .mask_inst=0x3, .mask_w=0x1, .has_w=true,
-     .has_s=true, .has_operands=true, .has_displacement=true,
-     .has_data=true, .has_mod=true, .has_rm=true},
-    {.id=8, .name="add", .inst_enc=0b00000100, .mask_inst=0x1, .mask_w=0x1,
-     .has_data=true, .has_w=true, .parse_reg={.tag = P_REG_FIXED, .fixed=0x0}},
-};
@@ -1,119 +0,0 @@
-package decoder_8086
-
-import "core:os"
-import "core:fmt"
-
-Register :: struct {
-    fullname: string,
-    bytename: string,
-    value: struct #raw_union {
-        using _: struct {
-            low, high: byte,
-        },
-        full: u16,
-    },
-    code: u8,
-}
-
-RegMemMode :: enum {
-    Memory00 = 0b00,
-    Memory08 = 0b01,
-    Memory16 = 0b10,
-    Register = 0b11,
-};
-
-registers := [8]Register {
-    {fullname = "ax", bytename = "al", code = 0b000},
-    {fullname = "cx", bytename = "cl", code = 0b001},
-    {fullname = "dx", bytename = "dl", code = 0b010},
-    {fullname = "bx", bytename = "bl", code = 0b011},
-    {fullname = "sp", bytename = "ah", code = 0b100},
-    {fullname = "bp", bytename = "ch", code = 0b101},
-    {fullname = "si", bytename = "dh", code = 0b110},
-    {fullname = "di", bytename = "bh", code = 0b111},
-}
-
-Instruction :: struct {
-    mask: u8,
-    encoding: u8,
-    name: string,
-    desc: string,
-}
-
-instructions := [?]Instruction {
-    { mask = 0b11111100, encoding = 0b10001000, name = "mov", desc = "Register/memory to/from register" },
-    { mask = 0b11111110, encoding = 0b11000110, name = "mov", desc = "Immediate to register/memory" },
-    { mask = 0b11110000, encoding = 0b10110000, name = "mov", desc = "Immediate to register" },
-    { mask = 0b11111110, encoding = 0b10100000, name = "mov", desc = "Memory to accumulator" },
-    { mask = 0b11111110, encoding = 0b10100010, name = "mov", desc = "Accumulator to memory" },
-    { mask = 0b11111111, encoding = 0b10001110, name = "mov", desc = "Register/memory to segment register" },
-    { mask = 0b11111111, encoding = 0b10001100, name = "mov", desc = "Segment register to register/memory" },
-}
-
-inst_map := make(map[u8]Instruction)
-
-main :: proc() {
-    ax := registers[0]
-    ax.value.full = 52428
-    f,err := os.open(len(os.args) > 1 ? os.args[1] : "./asm_files/01-02-39.bin")
-    if err != os.ERROR_NONE {
-        os.exit(1)
-    }
-    defer os.close(f)
-
-    data := make([]u8, 512)
-    bytes_read, err2 := os.read(f, data)
-    if err2 != nil {
-        // ...
-        os.exit(1)
-    }
-
-    for inst in instructions {
-        inst_map[inst.encoding] = inst
-    }
-
-    if true {
-        for i in 0..<bytes_read {
-            fmt.printfln("%b", data[i])
-            mask: u8 = 0b11111111
-            for i in 0..=4 {
-                encoding := data[i] & mask
-                if inst, ok := inst_map[encoding]; ok {
-                    fmt.printfln("%b, %v", encoding, inst.desc)
-                    // fmt.println(inst.desc)
-                    break
-                }
-                mask <<= 1
-            }
-            // fmt.println("=============")
-        }
-        os.exit(0)
-    }
-
-    read_next := false
-    src_dst := true
-    is_word := false
-    prev :u8 = 0
-    fmt.println("bits 16\n")
-    for i in 0..<bytes_read {
-        b := data[i]
-        if read_next {
-            mod := (b & 0b11000000) >> 6
-            reg := (b & 0b00111000) >> 3
-            rm  := b & 0b00000111
-            src_name := is_word ? registers[reg].fullname : registers[reg].bytename
-            dst_name := is_word ? registers[rm].fullname : registers[rm].bytename
-            fmt.printfln("mov %s, %s     ;; %b  %b", dst_name, src_name, prev, b)
-            read_next = false
-            continue
-        }
-        if b == 0b10001001 {
-            read_next = true
-            is_word = true
-        } else if b == 0b10001000 {
-            read_next = true
-            is_word = false
-        }
-        prev = b
-    }
-}
@@ -0,0 +1,279 @@
+package sim_8086
+
+import "core:fmt"
+import "core:math"
+import "core:strings"
+
+SEGMENT_REGISTER_START :: 8
+
+get_i16 :: proc(data: []u8) -> i16 {
+    return (i16)(data[1]) << 8 | (i16)(data[0])
+}
+
+get_op :: proc(inst: Instruction) -> (Op, bool) {
+    op: Op
+    interseg: bool
+    if inst.opname == .TBD2 {
+        switch inst.raw_data[1] & 0b00111000 >> 3 {
+        case 0b000: op = .INC
+        case 0b001: op = .DEC
+        case 0b010: op = .CALL
+        case 0b011: op = .CALL; interseg = true
+        case 0b100: op = .JMP
+        case 0b101: op = .JMP; interseg = true
+        case 0b110: op = .PUSH
+        }
+    } else if inst.opname == .TBD5 {
+        switch inst.raw_data[1] & 0b00111000 >> 3 {
+        case 0b000: op = .TEST
+        case 0b001: op = .DEC
+        case 0b010: op = .NOT
+        case 0b011: op = .NEG
+        case 0b100: op = .MUL
+        case 0b101: op = .IMUL
+        case 0b110: op = .DIV
+        case 0b111: op = .IDIV
+        }
+    } else if inst.opname == .TBD6 {
+        switch inst.raw_data[1] & 0b00111000 >> 3 {
+        case 0b000: op = .ROL
+        case 0b001: op = .ROR
+        case 0b010: op = .RCL
+        case 0b011: op = .RCR
+        case 0b100: op = .SHL
+        case 0b101: op = .SHR
+        case 0b111: op = .SAR
+        }
+    } else if inst.opname == .TBD1 || inst.opname == .TBD3 || inst.opname == .TBD4 {
+        bits: u8
+        if inst.opname == .TBD1 || inst.opname == .TBD3 {
+            bits = inst.raw_data[0] & 0b00111000 >> 3
+        } else {
+            bits = inst.raw_data[1] & 0b00111000 >> 3
+        }
+        switch bits {
+        case 0b000: op = .ADD
+        case 0b001: op = .OR
+        case 0b010: op = .ADC
+        case 0b011: op = .SBB
+        case 0b100: op = .AND
+        case 0b101: op = .SUB
+        case 0b110: op = .XOR
+        case 0b111: op = .CMP
+        }
+    } else {
+        op = inst.opname
+    }
+    return op, interseg
+}
+
+parse_operand :: proc(inst: InstructionInfo, opinfo: OperandInfo, data: []u8, processed: ^int,
+                      total_bytes_processed: int, word: bool, has_segreg: Maybe(RegisterId)) -> Operand {
+    operand: Operand = None{}
+    switch opinfo {
+    case .None:
+    case .Register, .SegmentRegister:
+        reg: u8
+        switch inst.reg_info {
+        case .None: panic("Register is required but the encoded location is not provided")
+        case .FirstByteLast3:    reg = data[0] & 0b111
+        case .FirstByteMiddle3:  reg = (data[0] >> 3) & 0b111
+        case .SecondByteMiddle3: reg = (data[1] >> 3) & 0b111
+        case .SecondByteLast3:   reg = data[1] & 0b111
+        }
+        if opinfo == .SegmentRegister {
+            operand = (RegisterId){name = Register(SEGMENT_REGISTER_START + (int)(reg)), access = .Full}
+        } else if word {
+            operand = RegisterId { name = Register(reg), access = .Full }
+        } else {
+            operand = RegisterId { name = Register(reg % 4), access = reg < 4 ? .Low : .High }
+        }
+    case .RegisterMemory:
+        mod := data[1] >> 6
+        rm := data[1] & 0b111
+        processed^ += 1
+        op: Operand
+        if mod == 0 {
+            if rm == 0b110 {
+                // op = DirectAddress { value = get_i16(data[2:]) }
+                op = (DirectAddress)(get_i16(data[2:]))
+                processed^ += 2
+            } else {
+                op = MemoryAddr{ addr_id = rm }
+            }
+        } else if mod == 1 {
+            // NOTE: Per the 8086 manual in order to detect signed displacement, you have
+            // to sign extend a byte to a word. In Odin like in other languages, first
+            // cast to an i8, before casting to an i16 and it'll sign extend
+            op = MemoryAddr{ addr_id = rm , displacement = i16(i8(data[2])) }
+            processed^ += 1
+        } else if mod == 2 {
+            op = MemoryAddr{ addr_id = rm , displacement = get_i16(data[2:]) }
+            processed^ += 2
+        } else if mod == 3 {
+            if word {
+                op = RegisterId { name = Register(rm), access = .Full }
+            } else {
+                op = RegisterId { name = Register(rm % 4), access = rm < 4 ? .Low : .High }
+            }
+        }
+        operand = op
+    case .Immediate:
+        data_idx := processed^
+            word_signed := word
+        if inst.has_sign_extension {
+            word_signed &&= data[0] & 0b0000_0010 == 0
+        }
+        value: i16 = word_signed ? get_i16(data[data_idx:]) : i16(i8(data[data_idx]))
+        operand = Immediate { value = value, size = word_signed ? ._16 : ._8 }
+        processed^ += word_signed ? 2 : 1
+    case .Accumulator:
+        operand = RegisterId { name = .ax, access = word ? .Full : .Low }
+    case .DirectAddress:
+        // operand = DirectAddress { value = get_i16(data[1:]) }
+        operand = (DirectAddress)(get_i16(data[1:]))
+        processed^ += 2
+    case .Jump:
+        processed^ += 1
+        // NOTE: In order to mimic the label offset, you have to take the value you got and add two
+        operand = (Jump)((i8)(data[1]) + 2)
+    case .VariablePort:
+        // NOTE: This isn't documented in the manual, but you can tell if we need to use
+        // the dx register or an immediate if the 4th LSB bit is set
+        if (data[0] & 0b1000) >> 3 == 1 {
+            operand = RegisterId { name = .dx, access = .Full }
+        } else {
+            operand = Immediate { value = i16(i8(data[1])), size = ._8 }
+            processed^ += 1
+        }
+    case .ShiftRotate:
+        v_flag := data[0] & 0b10 != 0
+        operand = v_flag ? RegisterId { name = .cx, access = .Low } : Immediate { value = 1 }
+    case .Repeat:
+        bits := (data[1] & 0b1110) >> 1
+        w := (data[1] & 0b1) == 1 ? "w" : "b"
+        rep: string
+        switch bits {
+        case 0b010: rep = "movs"
+        case 0b011: rep = "cmps"
+        case 0b101: rep = "stos"
+        case 0b110: rep = "lods"
+        case 0b111: rep = "scas"
+        }
+        operand = Repeat(fmt.aprintf("%s%s", rep, w))
+        processed^ += 1
+    case .DirectWithinSegment:
+        value := (int)(get_i16(data[1:])) + total_bytes_processed + 3
+        operand = Immediate { value = i16(value), size = ._16 }
+        processed^ += 2
+    case .Intersegment:
+        operand = Intersegment {
+            ip = get_i16(data[1:]),
+            cs = get_i16(data[3:]),
+        }
+        processed^ += 4
+    }
+    return operand
+}
+
+decode_data :: proc(inst_list: ^[dynamic]Instruction, data: []u8, bytes_to_read: int) -> int {
+    idx := 0
+    has_segment: Maybe(RegisterId)
+    has_lock: bool
+    total_bytes_processed: int
+    for idx < bytes_to_read {
+        instruction: Instruction
+        processed := 1
+        curr_byte := data[idx]
+
+        found_inst: bool
+        inst: InstructionInfo
+        for i in instructions {
+            if i.encoding == (curr_byte & i.mask) {
+                found_inst = true
+                inst = i
+                break
+            }
+        }
+        if !found_inst {
+            instruction = {
+                opname = .UNKNOWN,
+                bytes_read = 1,
+                raw_data = data[idx:idx+1],
+            }
+            append(inst_list, instruction)
+            idx += 1
+            continue
+        }
+
+        // Here we check if the instruction affects the next instruction
+        if inst.opname == .LOCK {
+            has_lock = true
+            idx += 1
+            continue
+        } else if inst.opname == .SEGMENT {
+            reg := (curr_byte & 0b11000) >> 3
+            has_segment = RegisterId { name = Register(SEGMENT_REGISTER_START+reg) }
+            idx += 1
+            continue
+        } else if inst.opname == .AAM {
+            processed += 1
+        }
+
+        debug_str: string
+        // NOTE: This is a special case because it matches the bit pattern of .TBD5,
+        // but the instruction itself is different
+        if inst.opname == .TBD5 && (data[idx] & 0xFF) == 0b11110110 && (data[idx+1] & 0b00111000) == 0 {
+            inst = test_inst
+        }
+
+        src_opr: Operand
+        dst_opr: Operand
+
+        word: bool
+        flip: bool
+        op: Operand
+
+        if inst.has_flip {
+            flip = curr_byte & 2 != 0
+        }
+
+        #partial switch inst.word_size {
+        case .LastBit: word = curr_byte & 1 == 1
+        case .FourthBit: word = curr_byte & 0b0000_1000 != 0
+        case .Always16: word = true
+        }
+
+        dst_opr = parse_operand(inst, inst.dst, data[idx:], &processed, total_bytes_processed, word, has_segment)
+        src_opr = parse_operand(inst, inst.src, data[idx:], &processed, total_bytes_processed, word, has_segment)
+
+        if flip {
+            src_opr, dst_opr = dst_opr, src_opr
+        }
+
+        processed += inst.consume_extra_bytes
+
+        instruction.src = src_opr
+        instruction.dst = dst_opr
+        instruction.is_word = word
+        instruction.bytes_read = processed
+        instruction.raw_data = data[idx:idx+processed]
+        instruction.debug_msg = debug_str
+        instruction.info = inst
+        instruction.has_lock = has_lock
+        instruction.has_segment = has_segment
+        instruction.segment_offset += total_bytes_processed
+        instruction.opname = inst.opname
+        instruction.opname,instruction.indirect_intersegment = get_op(instruction)
+
+        // fmt.println(parsed_inst)
+        append(inst_list, instruction)
+
+        idx += processed
+
+        has_lock = false
+        has_segment = nil
+        total_bytes_processed = idx
+    }
+    return total_bytes_processed
+}
@@ -0,0 +1,165 @@
+package sim_8086
+
+import "core:os"
+import "core:fmt"
+import "core:math"
+import "core:strings"
+import "core:reflect"
+import "core:strconv"
+
+get_ip :: proc(cpu: ^Cpu) -> int { return int(cpu.registers[.ip].full) }
+
+get_effective_address_value :: proc(cpu: ^Cpu, id: u8) -> i16 {
+    switch id {
+    case 0: return cpu.registers[.bx].full + cpu.registers[.si].full
+    case 1: return cpu.registers[.bx].full + cpu.registers[.di].full
+    case 2: return cpu.registers[.bp].full + cpu.registers[.si].full
+    case 3: return cpu.registers[.bx].full + cpu.registers[.di].full
+    case 4: return cpu.registers[.si].full
+    case 5: return cpu.registers[.di].full
+    case 6: return cpu.registers[.bp].full
+    case 7: return cpu.registers[.bx].full
+    }
+    return -1
+}
+
+perform_load :: proc(cpu: ^Cpu, operand: Operand, is_word: bool) -> i16 {
+    #partial switch opr in operand {
+    case Immediate:
+        return i16(opr.value)
+    case RegisterId:
+        reg_val := cpu.registers[opr.name]
+        switch opr.access {
+        case .Low, .High:
+            return i16(opr.access == .Low ? reg_val.low : reg_val.high)
+        case .Full:
+            return i16(reg_val.full)
+        }
+    case DirectAddress:
+        value: i16
+        if is_word {
+            value = i16(u16(cpu.memory[opr+1] << 8) | u16(cpu.memory[opr]))
+        } else {
+            value = i16(cpu.memory[opr])
+        }
+        return value
+    case MemoryAddr:
+        value: i16
+        idx := get_effective_address_value(cpu, opr.addr_id) + opr.displacement
+        if is_word {
+            value = i16(u16(cpu.memory[idx+1] << 8) | u16(cpu.memory[idx]))
+        } else {
+            value = i16(cpu.memory[idx])
+        }
+        return value
+    }
+    return 0
+}
+
+check_flags :: proc(cpu: ^Cpu, flags: bit_set[Flag], dst: i16, src: i16, result: i16, is_add: bool) {
+    if .ZF in flags do cpu.flags[.ZF] = result == 0
+    if .SF in flags do cpu.flags[.SF] = (result >> 15) & 0x1 == 1
+    if .CF in flags {
+        cpu.flags[.CF] = is_add ? u32(dst) + u32(src) > 0xFFFF : src > dst
+    }
+    if .AF in flags {
+        lhs, rhs := dst & 0xF, src & 0xF
+        cpu.flags[.AF] = is_add ? lhs + rhs > 15 : lhs < rhs
+    }
+    if .PF in flags {
+        val := result
+        bit_count := 0
+        val &= 0x00FF
+        for val != 0 {
+            if val & 0x1 == 1 {
+                bit_count += 1
+            }
+            val >>= 1
+        }
+        cpu.flags[.PF] = bit_count % 2 == 0
+    }
+}
+
+perform_store :: proc(cpu: ^Cpu, value: i16, operand: Operand, is_word: bool) {
+    #partial switch opr in operand {
+    case RegisterId:
+        switch opr.access {
+        case .Low:
+            cpu.registers[opr.name].low = u8(value)
+        case .High:
+            cpu.registers[opr.name].high = u8(value)
+        case .Full:
+            cpu.registers[opr.name].full = i16(value)
+        }
+    case DirectAddress:
+        cpu.memory[opr] = u8(value)
+        if is_word do cpu.memory[opr+1] = u8((u16(value) & 0xFF00) >> 8)
+    case MemoryAddr:
+        effective_addr_val := get_effective_address_value(cpu, opr.addr_id)
+        addr := effective_addr_val + opr.displacement
+        cpu.memory[addr] = u8(value)
+        if is_word do cpu.memory[addr+1] = u8((u16(value) & 0xFF00) >> 8)
+    }
+}
+
+execute_instruction :: proc(cpu: ^Cpu, inst: Instruction) {
+    if jmp_offset,ok := inst.src.(Jump); ok {
+        jump: bool
+        #partial switch inst.opname {
+        case .JNZ, .JNE: jump = !cpu.flags[.ZF]
+        case .JE, .JZ:   jump =  cpu.flags[.ZF]
+        case .JP, .JPE:  jump =  cpu.flags[.PF]
+        case .JB, .JNAE: jump =  cpu.flags[.CF]
+
+        case .LOOP:
+            cpu.registers[.cx].full -= 1
+            jump = cpu.registers[.cx].full != 0
+        case .LOOPNZ, .LOOPNE:
+            cpu.registers[.cx].full -= 1
+            // According to this resource, the loopnz inst does not change any flags
+            // https://yassinebridi.github.io/asm-docs/8086_instruction_set.html#LOOPNZ
+            // check_zero_flag(cpu, cpu.registers[.cx].full)
+            jump = cpu.registers[.cx].full != 0 && !cpu.flags[.ZF]
+        }
+        if jump {
+            cpu.registers[.ip].full += i16(jmp_offset)
+            cpu.registers[.ip].full -= i16(inst.bytes_read)
+        }
+        return
+    }
+    status_flags := bit_set[Flag]{.OF, .SF, .ZF, .AF, .PF, .CF}
+    #partial switch inst.opname {
+    case .MOV:
+        src_val := perform_load(cpu, inst.src, inst.is_word)
+        perform_store(cpu, src_val, inst.dst, inst.is_word)
+    case .ADD:
+        src_val := perform_load(cpu, inst.src, inst.is_word)
+        dst_val := perform_load(cpu, inst.dst, inst.is_word)
+        val := dst_val + src_val
+        perform_store(cpu, val, inst.dst, inst.is_word)
+        check_flags(cpu, status_flags, dst_val, src_val, val, true)
+    case .SUB:
+        src_val := perform_load(cpu, inst.src, inst.is_word)
+        dst_val := perform_load(cpu, inst.dst, inst.is_word)
+        val := dst_val - src_val
+        perform_store(cpu, val, inst.dst, inst.is_word)
+        check_flags(cpu, status_flags, dst_val, src_val, val, false)
+    case .CMP:
+        src_val := perform_load(cpu, inst.src, inst.is_word)
+        dst_val := perform_load(cpu, inst.dst, inst.is_word)
+        val := dst_val - src_val
+        check_flags(cpu, status_flags, dst_val, src_val, val, false)
+    }
+}
+
+execute_instructions :: proc(cpu: ^Cpu, instructions: DecodedInstructions) {
+    halt := false
+    for !halt && get_ip(cpu) < instructions.total_bytes_decoded {
+        inst,ok := instructions.inst_map[get_ip(cpu)]
+        if !ok {
+            panic("Something went wrong with a jump, most likely")
+        }
+        cpu.registers[.ip].full += i16(inst.bytes_read)
+        execute_instruction(cpu, inst)
+    }
+}
@@ -0,0 +1,307 @@
+package sim_8086
+
+Op :: enum {
+    UNKNOWN,
+    TBD1,
+    TBD2,
+    TBD3,
+    TBD4,
+    TBD5,
+    TBD6,
+    MOV,
+    PUSH,
+    POP,
+    XCHG,
+    IN,
+    OUT,
+    XLAT,
+    LEA,
+    LDS,
+    LES,
+    LAHF,
+    SAHF,
+    PUSHF,
+    POPF,
+    ADD,
+    ADC,
+    INC,
+    AAA,
+    DAA,
+    SUB,
+    SBB,
+    DEC,
+    NEG,
+    MUL,
+    IMUL,
+    CMP,
+    AAS,
+    DAS,
+    AAM,
+    DIV,
+    IDIV,
+    AAD,
+    CBW,
+    CWD,
+    ROL,
+    ROR,
+    RCL,
+    RCR,
+    SHL,
+    SHR,
+    SAR,
+    NOT,
+    TEST,
+    OR,
+    AND,
+    XOR,
+    REP,
+    RET,
+    RETF,
+    INT,
+    INT3,
+    INTO,
+    IRET,
+    CLC,
+    CMC,
+    STC,
+    CLD,
+    STD,
+    CLI,
+    STI,
+    HLT,
+    WAIT,
+    ESC,
+    LOCK,
+    SEGMENT,
+    CALL,
+    JMP,
+    JNZ,
+    JNE,
+    JNGE,
+    JE,
+    JZ,
+    JL,
+    JLE,
+    JNG,
+    JB,
+    JNAE,
+    JP,
+    JPE,
+    JNA,
+    JBE,
+    JO,
+    JS,
+    JNL,
+    JGE,
+    JNLE,
+    JG,
+    JNB,
+    JAE,
+    JNBE,
+    JA,
+    JNP,
+    JPO,
+    JNO,
+    JNS,
+    LOOP,
+    LOOPZ,
+    LOOPNZ,
+    LOOPNE,
+    JCXZ,
+}
+
+// TODO: We should figure out another way of handling this case. The way we're doing it
+// isn't that great; we return a string with the instruction name, but ideally we have all
+// the instructions accounted for, because eventually we will need the final parsed
+// instruction to contain all the information related to it
+// test_inst := InstructionInfo {
+//     opname = .NOT, desc = "", mask = 0b11111110, encoding = 0b11110110,
+//     dst = .RegisterMemory, src = .Immediate, word_size = .LastBit
+// }
+test_inst := InstructionInfo {
+    opname = .TEST, desc = "", mask = 0b11111110, encoding = 0b11110110,
+    dst = .RegisterMemory, src = .Immediate, word_size = .LastBit
+}
+
+instructions := [?]InstructionInfo {
+    { opname = .TBD1, desc = "Immediate to accumulator",
+      mask = 0b11000110, encoding = 0b00000100, check_second_encoding = true,
+      dst = .Accumulator, src = .Immediate,
+      word_size = .LastBit, },
+    { opname = .TBD2, desc = "", check_second_encoding = true,
+      mask = 0b11111110, encoding = 0b11111110,
+      src = .RegisterMemory,
+      word_size = .LastBit, },
+    { opname = .TBD3, desc = "", check_second_encoding = true,
+      mask = 0b11000100, encoding = 0b00000000,
+      dst = .RegisterMemory, src = .Register,
+      word_size = .LastBit, reg_info = .SecondByteMiddle3, has_flip = true },
+    { opname = .TBD4, desc = "", check_second_encoding = true,
+      mask = 0b11111100, encoding = 0b10000000,
+      dst = .RegisterMemory, src = .Immediate,
+      word_size = .LastBit, has_sign_extension = true },
+    { opname = .TBD5, desc = "", check_second_encoding = true,
+      mask = 0b11111110, encoding = 0b11110110,
+      // dst = .Immediate, src = .RegisterMemory, word_size = .LastBit, },
+      src = .RegisterMemory, word_size = .LastBit, },
+    { opname = .TBD6, desc = "", check_second_encoding = true,
+      mask = 0b11111100, encoding = 0b11010000,
+      dst = .RegisterMemory, src = .ShiftRotate, word_size = .LastBit, },
+    { opname = .MOV, desc = "Register/memory to/from register",
+      mask = 0b11111100, encoding = 0b10001000,
+      dst = .RegisterMemory, src = .Register,
+      word_size = .LastBit, reg_info = .SecondByteMiddle3, has_flip = true },
+    { opname = .MOV, desc = "Immediate to register/memory",
+      mask = 0b11111110, encoding = 0b11000110,
+      dst = .RegisterMemory, src = .Immediate,
+      word_size = .LastBit, },
+    { opname = .MOV, desc = "Immediate to register",
+      mask = 0b11110000, encoding = 0b10110000,
+      dst = .Register, src = .Immediate,
+      word_size = .FourthBit, reg_info = .FirstByteLast3 },
+    { opname = .MOV, desc = "Memory to accumulator",
+      mask = 0b11111110, encoding = 0b10100000,
+      dst = .Accumulator, src = .DirectAddress,
+      word_size = .LastBit, },
+    { opname = .MOV, desc = "Accumulator to memory",
+      mask = 0b11111110, encoding = 0b10100010,
+      dst = .DirectAddress, src = .Accumulator,
+      word_size = .LastBit, },
+    // NOTE: There's another instruction but it seems like it just flips, and while not specified
+    // it seems like it has an undocumented flip bit just like the others
+    { opname = .MOV, desc = "Register/memory to segment register",
+      mask = 0b11111101, encoding = 0b10001100,
+      dst = .RegisterMemory, src = .SegmentRegister,
+      reg_info = .SecondByteMiddle3, word_size = .Always16, has_flip = true },
+    { opname = .PUSH, desc = "", mask = 0b11111000, encoding = 0b01010000,
+      src = .Register, reg_info = .FirstByteLast3,
+      word_size = .Always16, },
+    { opname = .PUSH, desc = "", mask = 0b11100111, encoding = 0b00000110,
+      src = .SegmentRegister, reg_info = .FirstByteMiddle3,
+      word_size = .Always16, },
+    { opname = .POP, desc = "", mask = 0b11111111, encoding = 0b10001111,
+      src = .RegisterMemory, word_size = .Always16 },
+    { opname = .POP, desc = "", mask = 0b11111000, encoding = 0b01011000,
+      src = .Register, reg_info = .FirstByteLast3,
+      word_size = .Always16, },
+    { opname = .POP, desc = "", mask = 0b11100111, encoding = 0b00000111,
+      src = .SegmentRegister, reg_info = .FirstByteMiddle3,
+      word_size = .Always16, },
+    { opname = .XCHG, desc = "", mask = 0b11111110, encoding = 0b10000110,
+      dst = .RegisterMemory, src = .Register,
+      reg_info = .SecondByteMiddle3, word_size = .LastBit, has_flip = true },
+    { opname = .XCHG, desc = "", mask = 0b11111000, encoding = 0b10010000,
+      dst = .Accumulator, src = .Register,
+      reg_info = .FirstByteLast3, has_flip = true, word_size = .Always16 },
+    { opname = .IN, desc = "", mask = 0b11111110, encoding = 0b11100100,
+      dst = .Accumulator, src = .Immediate, word_size = .LastBit },
+    { opname = .IN, desc = "", mask = 0b11111110, encoding = 0b11101100,
+      dst = .Accumulator, src = .VariablePort, word_size = .LastBit, },
+    { opname = .OUT, desc = "", mask = 0b11111110, encoding = 0b11100110,
+      dst = .VariablePort, src = .Accumulator, word_size = .LastBit },
+    { opname = .OUT, desc = "", mask = 0b11111110, encoding = 0b11101110,
+      dst = .VariablePort, src = .Accumulator, word_size = .LastBit, },
+    { opname = .TEST, desc = "", mask = 0b11111110, encoding = 0b10101000,
+      dst = .Accumulator, src = .Immediate, word_size = .LastBit },
+    { opname = .XLAT, desc = "", mask = 0b11111111, encoding = 0b11010111,},
+    { opname = .LEA, desc = "", mask = 0b11111111, encoding = 0b10001101,
+      dst = .Register, src = .RegisterMemory,
+      reg_info = .SecondByteMiddle3, word_size = .Always16 },
+    { opname = .LDS, desc = "", mask = 0b11111111, encoding = 0b11000101, 
+      dst = .Register, src = .RegisterMemory,
+      reg_info = .SecondByteMiddle3, word_size = .Always16 },
+    { opname = .LES, desc = "", mask = 0b11111111, encoding = 0b11000100,
+      dst = .Register, src = .RegisterMemory,
+      reg_info = .SecondByteMiddle3, word_size = .Always16 },
+    { opname = .LAHF,  desc = "", mask = 0b11111111, encoding = 0b10011111,},
+    { opname = .SAHF,  desc = "", mask = 0b11111111, encoding = 0b10011110,},
+    { opname = .PUSHF, desc = "", mask = 0b11111111, encoding = 0b10011100,},
+    { opname = .POPF,  desc = "", mask = 0b11111111, encoding = 0b10011101,},
+    { opname = .INC, desc = "", mask = 0b11111000, encoding = 0b01000000,
+      src = .Register, reg_info = .FirstByteLast3, word_size = .Always16 },
+    { opname = .AAA,  desc = "", mask = 0b11111111, encoding = 0b00110111,},
+    { opname = .DAA,  desc = "", mask = 0b11111111, encoding = 0b00100111,},
+    { opname = .DEC, desc = "", mask = 0b11111000, encoding = 0b01001000, 
+      src = .Register, reg_info = .FirstByteLast3, word_size = .Always16 },
+    { opname = .AAS,  desc = "", mask = 0b11111111, encoding = 0b00111111,},
+    { opname = .DAS,  desc = "", mask = 0b11111111, encoding = 0b00101111,},
+    { opname = .AAM,  desc = "", mask = 0b11111111, encoding = 0b11010100,},
+    { opname = .AAD,  desc = "", mask = 0b11111111, encoding = 0b11010101, consume_extra_bytes = 1 },
+    { opname = .CBW,  desc = "", mask = 0b11111111, encoding = 0b10011000,},
+    { opname = .CWD,  desc = "", mask = 0b11111111, encoding = 0b10011001,},
+    { opname = .TEST, desc = "", mask = 0b11111100, encoding = 0b10000100,
+      dst = .RegisterMemory, src = .Register,
+      word_size = .LastBit, reg_info = .SecondByteMiddle3, has_flip = true },
+    { opname = .REP, desc = "", mask = 0b11111110, encoding = 0b11110010, src = .Repeat },
+    { opname = .RET, desc = "", mask = 0b11111111, encoding = 0b11000011,},
+    { opname = .RET, src = .Immediate, word_size = .Always16,
+      desc = "", mask = 0b11111111, encoding = 0b11000010,},
+    { opname = .RETF, desc = "", mask = 0b11111111, encoding = 0b11001011,},
+    { opname = .RETF, desc = "", mask = 0b11111111, encoding = 0b11001010,
+      src = .Immediate, word_size = .Always16 },
+    { opname = .INT, src = .Immediate, desc = "", mask = 0b11111111, encoding = 0b11001101,},
+    { opname = .INT3, desc = "", mask = 0b11111111, encoding = 0b11001100,},
+    { opname = .INTO, desc = "", mask = 0b11111111, encoding = 0b11001110,},
+    { opname = .IRET, desc = "", mask = 0b11111111, encoding = 0b11001111,},
+    { opname = .CLC,  desc = "", mask = 0b11111111, encoding = 0b11111000,},
+    { opname = .CMC,  desc = "", mask = 0b11111111, encoding = 0b11110101,},
+    { opname = .STC,  desc = "", mask = 0b11111111, encoding = 0b11111001,},
+    { opname = .CLD,  desc = "", mask = 0b11111111, encoding = 0b11111100,},
+    { opname = .STD,  desc = "", mask = 0b11111111, encoding = 0b11111101,},
+    { opname = .CLI,  desc = "", mask = 0b11111111, encoding = 0b11111010,},
+    { opname = .STI,  desc = "", mask = 0b11111111, encoding = 0b11111011,},
+    { opname = .HLT,  desc = "", mask = 0b11111111, encoding = 0b11110100,},
+    { opname = .WAIT, desc = "", mask = 0b11111111, encoding = 0b10011011,},
+    { opname = .LOCK, desc = "", mask = 0b11111111, encoding = 0b11110000,},
+    { opname = .SEGMENT, desc = "", mask = 0b11100111, encoding = 0b00100110,},
+    { opname = .CALL, desc = "", mask = 0b11111111, encoding = 0b10011010, src = .Intersegment  },
+    { opname = .JMP, desc = "", mask = 0b11111111, encoding = 0b11101010, src = .Intersegment  },
+    { opname = .JMP, desc = "", mask = 0b11111111, encoding = 0b11101001, src = .DirectWithinSegment },
+    { opname = .CALL, desc = "", mask = 0b11111111, encoding = 0b11101000, src = .DirectWithinSegment },
+    { opname = .JE,     mask = 0b11111111, encoding = 0b01110100, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JZ,     mask = 0b11111111, encoding = 0b01110100, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JL,     mask = 0b11111111, encoding = 0b01111100, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JNGE,   mask = 0b11111111, encoding = 0b01111100, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JLE,    mask = 0b11111111, encoding = 0b01111110, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JNG,    mask = 0b11111111, encoding = 0b01111110, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JB,     mask = 0b11111111, encoding = 0b01110010, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JNAE,   mask = 0b11111111, encoding = 0b01110010, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JBE,    mask = 0b11111111, encoding = 0b01110110, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JNA,    mask = 0b11111111, encoding = 0b01110110, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JP,     mask = 0b11111111, encoding = 0b01111010, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JPE,    mask = 0b11111111, encoding = 0b01111010, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JO,     mask = 0b11111111, encoding = 0b01110000, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JS,     mask = 0b11111111, encoding = 0b01111000, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JNE,    mask = 0b11111111, encoding = 0b01110101, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JNZ,    mask = 0b11111111, encoding = 0b01110101, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JNL,    mask = 0b11111111, encoding = 0b01111101, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JGE,    mask = 0b11111111, encoding = 0b01111101, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JNLE,   mask = 0b11111111, encoding = 0b01111111, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JG,     mask = 0b11111111, encoding = 0b01111111, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JNB,    mask = 0b11111111, encoding = 0b01110011, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JAE,    mask = 0b11111111, encoding = 0b01110011, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JNBE,   mask = 0b11111111, encoding = 0b01110111, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JA,     mask = 0b11111111, encoding = 0b01110111, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JNP,    mask = 0b11111111, encoding = 0b01111011, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JPO,    mask = 0b11111111, encoding = 0b01111011, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JNO,    mask = 0b11111111, encoding = 0b01110001, src = .Jump, desc = "Jump on not zero", },
+
+    { opname = .JNS,    mask = 0b11111111, encoding = 0b01111001, src = .Jump, desc = "Jump on not zero", },
+    { opname = .LOOP,   mask = 0b11111111, encoding = 0b11100010, src = .Jump, desc = "Jump on not zero", },
+    { opname = .LOOPZ,  mask = 0b11111111, encoding = 0b11100001, src = .Jump, desc = "Jump on not zero", },
+    { opname = .LOOPNZ, mask = 0b11111111, encoding = 0b11100000, src = .Jump, desc = "Jump on not zero", },
+    { opname = .JCXZ,   mask = 0b11111111, encoding = 0b11100011, src = .Jump, desc = "Jump on not zero", },
+}
@@ -1,53 +0,0 @@
-#pragma once
-#include <stdint.h>
-#include <stddef.h>
-
-typedef uint8_t   u8;
-typedef uint16_t  u16;
-typedef int16_t   i16;
-typedef int32_t   i32;
-typedef uint32_t  u32;
-typedef uint64_t  u64;
-typedef float     f32;
-typedef double    f64;
-typedef uintptr_t uptr;
-typedef char      sbyte;
-typedef ptrdiff_t size;
-typedef size_t    usize;
-
-enum OptionTag {NONE, SOME};
-
-#define OPTION(type)                                                    \
-    typedef struct                                                      \
-    {                                                                   \
-        enum OptionTag tag;                                             \
-        union {                                                         \
-            char none;                                                  \
-            type value;                                                 \
-        };                                                              \
-    } type##_opt;                                                       \
-                                                                        \
-    static inline type##_opt none_##type(void)                          \
-    {                                                                   \
-        return (type##_opt){ .tag = NONE, .none = 0 };                  \
-    }                                                                   \
-                                                                        \
-    static inline type##_opt some_##type(type value)                    \
-    {                                                                   \
-        return (type##_opt){ .tag = SOME, .value = value };             \
-    }                                                                   \
-                                                                        \
-    static inline int get_some_##type(type##_opt opt, type* out_value)  \
-    {                                                                   \
-        if (opt.tag != SOME) return 0;                                  \
-        *out_value = opt.value;                                         \
-        return 1;                                                       \
-    }
-
-#define IF_LET_SOME(type, var, opt)             \
-    type var;                                   \
-    if (get_some_##type(opt, &var))
-
-
-OPTION(u8)
-OPTION(u16)
@@ -0,0 +1,165 @@
+package sim_8086
+
+import "core:fmt"
+import "core:math"
+import "core:strings"
+import "core:reflect"
+
+instruction_builder := strings.builder_make()
+
+RIGHT_ALIGN_AMOUNT := 35
+
+operand_is :: proc($T: typeid, opr: Operand) -> bool {
+    _, ok := opr.(T)
+    return ok
+}
+
+calculate_effective_address :: proc(r_m: u8) -> string {
+    val: string
+    switch r_m {
+    case 0b000:
+        val = "bx + si"
+    case 0b001:
+        val = "bx + di"
+    case 0b010:
+        val = "bp + si"
+    case 0b011:
+        val = "bp + di"
+    case 0b100:
+        val = "si"
+    case 0b101:
+        val = "di"
+    case 0b110:
+        val = "bp"
+    case 0b111:
+        val = "bx"
+    }
+    return val
+}
+
+get_memory_string :: proc(memoryAddr: MemoryAddr, has_segment: Maybe(RegisterId)) -> string {
+    disp: string
+    value := memoryAddr.displacement
+    if value != 0 {
+        disp = fmt.aprintf(" %s %d", value > 0 ? "+" : "-", math.abs(value))
+    }
+    seg_string: string
+    if segreg, ok := has_segment.?; ok {
+        seg_string = fmt.aprintf("%s:", get_register_name(segreg))
+    }
+    text := fmt.aprintf("%s[%s%s]", seg_string, calculate_effective_address(memoryAddr.addr_id), disp)
+    return text
+}
+
+get_register_name :: proc(reg_id: RegisterId) -> string {
+    low_names := [?]string{"al", "cl", "dl", "bl"}
+    high_names := [?]string{"ah", "ch", "dh", "bh"}
+    switch reg_id.access {
+    case .Full: return reflect.enum_string(reg_id.name)
+    case .Low: return low_names[int(reg_id.name)]
+    case .High: return high_names[int(reg_id.name) % 4]
+    }
+    return ""
+}
+
+get_operand_string :: proc(operand: Operand, has_segment: Maybe(RegisterId)) -> string {
+    string_val: string
+    switch val in operand {
+    case None:
+        string_val = ""
+    case RegisterId:
+        string_val = get_register_name(val)
+    case Immediate:
+        string_val = fmt.aprintf("%d", val.value)
+    case MemoryAddr:
+        string_val = get_memory_string(val, has_segment)
+    case DirectAddress:
+        seg_string: string
+        if segreg, ok := has_segment.?; ok {
+            seg_string = fmt.aprintf("%s:", get_register_name(segreg))
+        }
+        string_val = fmt.aprintf("%s[%d]", seg_string, val)
+    case Jump:
+        string_val = fmt.aprintf("$%s%d", val >= 0 ? "+" : "", val)
+    case Repeat:
+        string_val = (string)(val)
+    case Intersegment:
+        string_val = fmt.aprintf("%d:%d", val.cs, val.ip)
+    }
+    return string_val
+}
+
+get_unknown_inst_string :: proc(inst: Instruction) -> string {
+    print_at_end := false
+    txt := "unknown instruction"
+    line := fmt.aprintf("%s %*[1]s %8b", txt, RIGHT_ALIGN_AMOUNT - len(txt), ";;", inst.raw_data[0])
+    return line
+}
+
+get_instruction_string :: proc(inst_info: InstructionInfo, instruction: Instruction) {
+    inst := instruction
+    src_is_imm := operand_is(Immediate, inst.src)
+    dst_is_bracketed := operand_is(MemoryAddr, inst.dst) || operand_is(DirectAddress, inst.dst)
+    src_is_bracketed := operand_is(MemoryAddr, inst.src) || operand_is(DirectAddress, inst.src)
+    shiftrot := inst_info.opname == .TBD6
+    size_string := ""
+    if ((src_is_imm && dst_is_bracketed) || (dst_is_bracketed && shiftrot)) || (src_is_bracketed && operand_is(None, inst.dst)) {
+        size_string = inst.is_word ? "word " : "byte "
+    }
+
+    if inst.has_lock {
+        fmt.sbprint(&instruction_builder, "lock ")
+    }
+
+    dst_str := get_operand_string(inst.dst, inst.has_segment)
+    src_str := get_operand_string(inst.src, inst.has_segment)
+    opname: string
+    is_interseg: bool
+
+    opname = strings.to_lower(reflect.enum_string(inst.opname))
+
+    if dst_str == "" {
+        interseg_string: string
+        if instruction.indirect_intersegment {
+            interseg_string = " far"
+        }
+        fmt.sbprintf(&instruction_builder, "%s%s %s%s", opname, interseg_string, size_string, src_str)
+    } else {
+        fmt.sbprintf(&instruction_builder, "%s %s%s, %s", opname, size_string, dst_str, src_str)
+    }
+
+    // Prepare padding and comment to add debug info
+    b_len := strings.builder_len(instruction_builder)
+    fmt.sbprintf(&instruction_builder, "%*[0]s", RIGHT_ALIGN_AMOUNT - b_len, ";;")
+
+    if inst.has_lock {
+        fmt.sbprintf(&instruction_builder, " lock")
+    }
+    if _,ok := inst.has_segment.?; ok {
+        fmt.sbprintf(&instruction_builder, " segment")
+    }
+    for i in 0..<inst.bytes_read {
+        fmt.sbprintf(&instruction_builder, " %08b", inst.raw_data[i])
+    }
+}
+
+print_instructions_stdout :: proc(instructions: []Instruction) {
+    last_opname: [3]byte
+    repeating_op_count := 0
+    fmt.println("bits 16\n")
+    for inst in instructions {
+        strings.builder_reset(&instruction_builder)
+        get_instruction_string(inst.info, inst)
+        op2 := strings.to_string(instruction_builder)
+        if op2[0:3] != string(last_opname[:]) {
+            if repeating_op_count > 0 {
+                fmt.println()
+            }
+            repeating_op_count = 0
+        } else {
+            repeating_op_count += 1
+        }
+        copy(last_opname[:], op2[0:3])
+        fmt.println(op2)
+    }
+}
@@ -0,0 +1,112 @@
+package sim_8086
+
+import "core:os"
+import path "core:path/filepath"
+import "core:fmt"
+import "core:math"
+import "core:strings"
+import "core:reflect"
+import "core:strconv"
+
+main :: proc() {
+    f,err := os.open(os.args[1])
+    if err != os.ERROR_NONE {
+        fmt.eprintln("ERROR:", err)
+        os.exit(1)
+    }
+    defer os.close(f)
+
+    what_to_print := len(os.args) >= 3 ? os.args[2] : ""
+
+    data := make([]u8, 1024)
+    bytes_read, err2 := os.read(f, data)
+    if err2 != nil {
+        // ...
+        os.exit(1)
+    }
+
+    // asdf :u16 = 0b00000110_11011101
+    // asdf2 :i16 = (i16)(asdf)
+    // fmt.printfln("%d", asdf2)
+    print_at_end := false
+    line_count := 0
+    instruction_list := make([dynamic]string, 0, 512)
+    instructions_list := make([dynamic]Instruction, 0, 512)
+
+    total_bytes := decode_data(&instructions_list, data[:], bytes_read)
+    inst_map := make(map[int]Instruction)
+    for inst in instructions_list {
+        inst_map[inst.segment_offset] = inst
+    }
+    decoded_insts := DecodedInstructions {
+        inst_list = instructions_list,
+        inst_map = inst_map,
+        total_bytes_decoded = total_bytes
+    }
+
+    cpu := Cpu {
+        memory = make([dynamic]u8, 1024 * 1024), // 1,048,576
+    }
+
+    num_idx := strings.last_index(os.args[1], "list-") + 5
+    if listing_num,ok := strconv.parse_int(os.args[1][num_idx:num_idx+4]); ok {
+        if listing_num > 42 {
+            execute_instructions(&cpu, decoded_insts)
+        }
+    }
+
+    if what_to_print == "registers" || what_to_print == "all" {
+        fmt.println("Registers")
+        for reg_val,name in cpu.registers {
+            full := fmt.aprintf("%s: %d ", name, i16(reg_val.full))
+            hex := fmt.aprintf("0x%04x ", u16(reg_val.full))
+            fmt.printf("%s %*[1]s %s %*[4]s %08b %08b",
+                       full, 18 - len(full), "|", hex, 10 - len(hex), "|", reg_val.high, reg_val.low)
+            fmt.println()
+        }
+        fmt.println("\nFlags")
+        for state,flag in cpu.flags {
+            fmt.printf("%c:%d  ",reflect.enum_string(flag)[0], state ? 1 : 0)
+        }
+        fmt.println()
+
+        failed_ref: bool
+        path,ok := strings.replace(os.args[1], ".bin", ".txt", 1)
+        ref_cpu,_ := parse_reference_cpu_state(path)
+        for reg_val,name in ref_cpu.registers {
+            if name == .ip && reg_val.full == 0 do continue
+            if cpu.registers[name].full != reg_val.full {
+                msg := "%s register does not match reference - Expected 0x%04x | Actual 0x%04x"
+                fmt.printfln(msg, name, reg_val.full, cpu.registers[name].full)
+                failed_ref = true
+            }
+        }
+        for f in Flag {
+            if ref_cpu.flags[f] != cpu.flags[f] {
+                msg := "%s flag does not match reference - Expected %d | Actual %d"
+                fmt.printfln(msg, f, ref_cpu.flags[f] ? 1 : 0, cpu.flags[f] ? 1 : 0)
+                failed_ref = true
+            }
+        }
+        if failed_ref {
+            os.exit(1)
+        }
+    }
+    if what_to_print == "instructions" || what_to_print == "all" {
+        print_instructions_stdout(instructions_list[:])
+    }
+    if len(os.args) > 3 && os.args[3] == "dump" {
+        f2,open_err := os.open("./listing-54.data", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
+        if open_err == nil {
+            bytes_written,write_err := os.write(f2, cpu.memory[:])
+            if write_err == nil {
+                fmt.println("Dumpped", bytes_written, "to disk: listing-54.data")
+            } else {
+                fmt.println("Error2:", write_err)
+            }
+        } else {
+            fmt.println("Error1:", open_err)
+        }
+        defer os.close(f)
+    }
+}
@@ -6,9 +6,14 @@ NC='\033[0m'

 make asm_files > /dev/null

+if [ ! "$(command -v ./sim8086)" ]; then
+    echo -e "\nError: 'sim8086' executable not found"
+    exit 1
+fi
+
 for ASM_BIN in asm_files/*.bin;
 do
-    ./decoder8086 "$ASM_BIN" > output.asm 2> /dev/null
+    ./sim8086 "$ASM_BIN" instructions > output.asm 2> /dev/null
    nasm output.asm -o output.bin 2> /dev/null
    ASM_FILE=${ASM_BIN%.*}.asm
    if [ ! -e  output.bin ]; then
@@ -0,0 +1,29 @@
+#!/bin/sh
+
+GREEN='\033[0;32m'
+RED='\033[0;31m'
+NC='\033[0m'
+
+make asm_files > /dev/null
+
+if [ ! "$(command -v ./sim8086)" ]; then
+    echo -e "\nError: 'sim8086' executable not found"
+    exit 1
+fi
+
+odin build . -out:sim8086
+
+for asm_txt in asm_files/*.txt;
+do
+    asm_listing=$(basename $asm_txt .txt)
+    output=$(./sim8086 asm_files/${asm_listing}.bin registers)
+    if [ $? -eq 1 ]; then
+        echo -e "Listing $asm_listing ${RED}Failed!${NC}"
+        echo "$output" | while IFS= read -r line; do
+            echo "$line"
+        done
+        echo -e ""
+    else
+        echo -e "Listing $asm_listing: ${GREEN}Succeded!${NC}"
+    fi
+done
@@ -0,0 +1,61 @@
+package sim_8086
+
+import "core:os"
+import "core:fmt"
+import "core:math"
+import "core:strings"
+import "core:strconv"
+import "core:reflect"
+
+get_cpu_register_by_name :: proc(cpu: ^Cpu, name: string) -> ^RegisterValue {
+    reg,_ := reflect.enum_from_name(Register, name)
+    return &cpu.registers[reg]
+}
+
+parse_reference_cpu_state :: proc(filename: string) -> (Cpu, bool) {
+    cpu: Cpu
+
+    data,ok := os.read_entire_file(filename)
+    if !ok {
+        return cpu, false
+    }
+    defer delete(data)
+
+    content := string(data)
+    lines := strings.split(content, "\n")
+    defer delete(lines)
+
+    for line in lines {
+        space_count := 0
+        for c,i in line {
+            if space_count == 0  && c != ' ' {
+                break
+            } else if c == ' ' {
+                space_count += 1
+            } else {
+                if line[i:i+5] == "flags" {
+                    idx := i + 7
+                    for idx < len(line) {
+                        flag_name := fmt.tprintf("%cF", line[idx])
+                        if flag,ok := reflect.enum_from_name(Flag, flag_name); ok {
+                            cpu.flags[flag] = true
+                        } else {
+                            fmt.eprintfln("Error parsing flag enum %s", flag_name)
+                        }
+                        idx += 1
+                    }
+                } else {
+                    reg_name := line[i:i+2]
+                    reg_value := get_cpu_register_by_name(&cpu, reg_name)
+                    hex_string := line[i+6:i+10]
+                    if hex_num,ok := strconv.parse_int(hex_string, 16); ok {
+                        reg_value^.full = i16(hex_num)
+                    }
+                }
+                break
+            }
+        }
+    }
+
+    return cpu, true
+}
@@ -0,0 +1,160 @@
+package sim_8086
+
+Register :: enum {
+    ax,
+    cx,
+    dx,
+    bx,
+    sp,
+    bp,
+    si,
+    di,
+    es,
+    cs,
+    ss,
+    ds,
+    ip,
+}
+
+RegisterValue :: struct #raw_union {
+    using _: struct {
+        low, high: byte,
+    },
+    full: i16,
+}
+
+Flag :: enum {
+    OF,
+    SF,
+    ZF,
+    AF,
+    PF,
+    CF,
+    // NOTE: These are the control flags, previous are status flags, justing noting in
+    // case we have to make that distinction in later modeling
+    TF,
+    DF,
+    IF,
+}
+
+WordSize :: enum {
+    None,
+    LastBit,
+    FourthBit,
+    Always8,
+    Always16,
+}
+
+None :: struct {}
+
+RegisterAccess :: enum {
+    Full,
+    Low,
+    High,
+}
+
+RegisterId :: struct {
+    name: Register,
+    access: RegisterAccess,
+}
+ImmediateSize :: enum {
+    _8,
+    _16,
+}
+Immediate :: struct {
+    value: i16,
+    size: ImmediateSize,
+}
+MemoryAddr :: struct {
+    addr_id: u8,
+    displacement: i16,
+    disp_size: ImmediateSize,
+}
+DirectAddress :: distinct i16
+Jump :: distinct i8
+Repeat :: string
+Intersegment :: struct {
+    ip: i16,
+    cs: i16,
+}
+
+Operand :: union {
+    None,
+    RegisterId,
+    Immediate,
+    MemoryAddr,
+    DirectAddress,
+    Jump,
+    Repeat,
+    Intersegment,
+}
+
+OperandInfo :: enum {
+    None,
+    Register,
+    SegmentRegister,
+    RegisterMemory,
+    Immediate,
+    Accumulator,
+    DirectAddress,
+    Jump,
+    VariablePort,
+    ShiftRotate,
+    Repeat,
+    DirectWithinSegment,
+    Intersegment,
+}
+
+RegisterEncodingBits :: enum {
+    None,
+    FirstByteLast3,
+    SecondByteMiddle3,
+    SecondByteLast3,
+    FirstByteMiddle3,
+}
+
+InstructionInfo :: struct {
+    mask: u8,
+    encoding: u8,
+    opname: Op,
+    desc: string,
+    src: OperandInfo,
+    dst: OperandInfo,
+    flags: bit_set[Flag],
+    word_size: WordSize,
+    reg_info: RegisterEncodingBits,
+    has_flip: bool,
+    has_sign_extension: bool,
+    check_second_encoding: bool,
+    consume_extra_bytes: int,
+    shift_rotate_flag: bool,
+}
+
+Instruction :: struct {
+    opname: Op,
+    src: Operand,
+    dst: Operand,
+    info: InstructionInfo,
+    is_word: bool,
+    indirect_intersegment: bool,
+    // TODO: This is trickier than I thought, it's more than just the one instruction
+    // that uses it
+    has_segment: Maybe(RegisterId),
+    has_lock: bool,
+    bytes_read: int,
+    segment_offset: int,
+    raw_data: []u8,
+    debug_msg: string,
+}
+
+DecodedInstructions :: struct {
+    inst_list: [dynamic]Instruction,
+    inst_map: map[int]Instruction,
+    total_bytes_decoded: int
+}
+
+Cpu :: struct {
+    flags: [Flag]bool,
+    registers: [Register]RegisterValue,
+    memory: [dynamic]u8,
+}
Author	SHA1	Message	Date
JosephFerano	51dae3128b	Listings 0056, 0057. Improve README	2025-06-14 10:31:35 +07:00
JosephFerano	85a8172923	Add .LOOP instruction, dump memory to disk with cli arg	2025-03-23 08:58:29 +07:00
JosephFerano	fafb440891	Listings 54 and 55	2025-03-23 08:58:12 +07:00
JosephFerano	df105ea3cf	Generalize with perform_load and perform_store, use bit_set for cpu flags	2025-03-22 18:54:36 +07:00
JosephFerano	831a307975	Fix and simplify (delete) all the signage stuff	2025-03-22 15:21:47 +07:00
JosephFerano	ea7b65994b	Fix IN and OUT instructions decoding	2025-03-22 15:20:48 +07:00
JosephFerano	ab2b107e7e	Listing 53	2025-03-22 15:09:00 +07:00
JosephFerano	da78d875c1	Effective address movs work, but at what cost?	2025-03-21 20:47:42 +07:00
JosephFerano	3ca4059c44	Listing 52	2025-03-21 20:47:34 +07:00
JosephFerano	11ccfe78a9	Handle Memory movs, change displacement from union to enum	2025-03-21 20:11:39 +07:00
JosephFerano	948960e8f5	Listing 51	2025-03-21 20:11:20 +07:00
JosephFerano	0e90e2c23c	Handle additional jumps for listing 50	2025-03-21 17:19:48 +07:00
JosephFerano	99fd7fabd7	Add inst decoded type for better modeling, handle jumps correctly with IP register	2025-03-21 16:33:58 +07:00
JosephFerano	d0f91f15f8	Listings 48 and 49	2025-03-21 16:33:24 +07:00
JosephFerano	731e5bd45d	CF, OF, and PF flags, keep values as i16, update ref test script	2025-03-20 20:22:12 +07:00
JosephFerano	5cf4768b80	Decode then check reference flags, change registers and flags to use enumerated arrays	2025-03-20 16:13:37 +07:00
JosephFerano	cd5eada115	Listing 47	2025-03-20 16:09:44 +07:00
JosephFerano	08874c4533	Use an enum to represent registers, parse txt files, check CPU state against expected	2025-03-20 13:06:33 +07:00
JosephFerano	305ac557fa	Move registers to CPU struct, start working on testing code	2025-03-20 09:44:41 +07:00
JosephFerano	b511c6a620	Clean up/inline functions and clear out TODOs	2025-03-20 08:19:20 +07:00
JosephFerano	266f7a7900	Factor out get/set actions to reduce duplication, execute add,sub,cmp and check flags	2025-03-19 21:10:22 +07:00
JosephFerano	863ccfc583	Convert TBD instruction op names to the actual enum variants, rather than strings	2025-03-19 21:09:42 +07:00
JosephFerano	fd8f696627	Listing 46	2025-03-19 21:07:11 +07:00
JosephFerano	a91c3d9ba9	Clean up operand code by removing unnecessary variants	2025-03-19 18:57:34 +07:00
JosephFerano	c312b7fd57	Fix register logic since we can access high and low parts, it's really ugly	2025-03-18 21:16:08 +07:00
JosephFerano	b78d043b6c	Add new listings, supply cs register, fix segreg mov instruction	2025-03-17 21:51:52 +07:00
JosephFerano	118ed482c1	Add listing 0044.txt, rm test files at the end of script	2025-03-16 23:55:26 +07:00
JosephFerano	6e7783c623	Bash script to compare expected output, print values in a way that's easy to test	2025-03-16 23:45:37 +07:00
JosephFerano	7e74d1e9a2	Print registers and execute basic mov instructions	2025-03-15 22:28:54 +07:00
JosephFerano	32ddb518e9	Break code up into files, delete C code, organize things better	2025-03-15 17:28:51 +07:00
JosephFerano	6909f75b35	Little bit more clean up	2025-03-13 21:59:37 +07:00
JosephFerano	d4216d793a	Listing 43/44 asm files	2025-03-13 17:50:58 +07:00
JosephFerano	3dca2254e1	Add helper proc to clean up the word/byte keyword	2025-03-13 17:50:32 +07:00
JosephFerano	460e1a8700	Little bit of clean up and organization	2025-03-13 12:46:25 +07:00
JosephFerano	fc02debf65	Last bunch of instructions to get listing 42 fully read	2025-03-12 23:46:47 +07:00
JosephFerano	babb07cb43	Segment register for memory addresses and lock string	2025-03-12 11:31:14 +07:00
JosephFerano	8967be44a0	Major refactor to define both operands so either can be empty	2025-03-12 11:07:40 +07:00
JosephFerano	08ef7d901b	IN, OUT, XLAT, LEA, LDS, LES, ADC	2025-03-07 19:27:01 +07:00
JosephFerano	782ff93ace	Handle accumulator differently, handle segment registers, handle unary, add instructions	2025-03-07 10:14:36 +07:00
JosephFerano	390fedc848	Add more instructions, add segment registers, move types up, read more data	2025-03-07 10:13:49 +07:00
JosephFerano	c7ee622847	Rename listing files	2025-03-03 20:40:47 +07:00
JosephFerano	6365bd73a0	Encode jump offsets, collect instruction lines as strings, print at end	2025-02-24 20:03:18 +07:00
JosephFerano	1f9837b256	Change how we detect explicit word sizes, fix data_idx	2025-02-23 12:05:56 +07:00
JosephFerano	c1799fcac2	Jump instructions and read opname from 3-bit pattern	2025-02-22 22:03:14 +07:00
JosephFerano	446848dffb	Generalizing data and operand bracketing, to make add instrunction work	2025-02-21 23:35:24 +07:00
JosephFerano	bc0a8b65eb	New declarative style instruction definition, generalized parsing	2025-02-21 21:53:11 +07:00
JosephFerano	f8f5744cd3	WIP: Separate parsing from printing, the easy way	2025-02-16 17:10:29 +07:00
JosephFerano	fbedf7cf67	Process mov instruction properly, 01-02-39.asm now decoded properly	2025-02-14 23:08:45 +07:00
JosephFerano	c5e9cfac44	Parse instruction function	2025-02-14 13:09:18 +07:00