asmhatreandClaude Sonnet 5.5
09af523f8c
NASM sources, DOSBox/FreeDOS Debug/Unicorn harness, captured output and 31 assertions backing the ankurm.com article "INT 3 vs INT 21h in 8086 Assembly". Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01KqJyCidz3ZgRyHABv2GVJh
65 lines
924 B
PHP
65 lines
924 B
PHP
; common.inc -- tiny output helpers shared by the demo programs (DOS .COM, NASM syntax)
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; print the '$'-terminated string at DS:DX (INT 21h, AH=09h)
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puts:
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mov ah, 09h
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int 21h
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ret
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; print CRLF
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crlf:
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mov dx, s_crlf
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jmp puts
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s_crlf db 0Dh, 0Ah, '$'
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; print AX as four hex digits using INT 21h AH=02h
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puthex16:
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push ax
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mov al, ah
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call puthex8
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pop ax
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puthex8:
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push ax
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shr al, 1
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shr al, 1
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shr al, 1
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shr al, 1
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call nib
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pop ax
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and al, 0Fh
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nib:
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add al, '0'
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cmp al, '9'
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jbe .ok
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add al, 7
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.ok:
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mov dl, al
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mov ah, 02h
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int 21h
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ret
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; print AX as unsigned decimal
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putdec:
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push bx
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push cx
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push dx
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xor cx, cx
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mov bx, 10
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.d1:
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xor dx, dx
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div bx
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push dx
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inc cx
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test ax, ax
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jnz .d1
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.d2:
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pop dx
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add dl, '0'
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mov ah, 02h
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int 21h
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loop .d2
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pop dx
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pop cx
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pop bx
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ret
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