88 lines
1.2 KiB
NASM
88 lines
1.2 KiB
NASM
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fcb1 equ 0x5C
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org 0x100
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jmp main
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%include "parse.inc"
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%include "print.inc"
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main mov di, 0x81
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mov al, 0x20
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mov ch, 0
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mov cl, [0x80]
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repe scasb
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repne scasb
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mov si, di
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call lodnum
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mov dx, ax
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test dx, ~0x83
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jnz drverr
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test dl, 0x80
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jz floppy
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call drverr
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drverr call putsh
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db "Failed to access drive", 0x0A, 0x0D, 0
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int 0x20
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floppy mov ax, 0x0201
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mov cx, 0x0001
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mov dh, 0
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mov bx, bs
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int 0x13
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jc drverr
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mov ax, [bs+0x18]
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call debug
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ret
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mov dx, fcb1
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mov ah, 0xF
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int 0x21
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test al, al
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jz .fok
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.ferr call putsh
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db "Failed to read input file", 0x0A, 0x0D, 0
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ret
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.fok mov si, prog
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; apply our target address
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.rloop mov dx, si
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mov ah, 0x1A
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int 0x21
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; increment address for next iteration
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add si, 0x80
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; do a read
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mov dx, fcb1
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mov ah, 0x14
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int 0x21
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; success: continue
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cmp al, 0
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jz .rloop
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; eof: break
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cmp al, 1
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jz .cok
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; segment wrap: fail
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cmp al, 2
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jz .ferr
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; we assume al=3: eof
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.cok nop
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mov ax, si
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sub ax, args
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call debug
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call putsh
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db "yay", 0x0A,0x0D,0
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ret
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; mov ax, 0x0201
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; mov cx, 0x0001
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; mov dh, 0
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; mov bx, bs
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; int 0x13
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; mov ax, [bs+0x18]
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;.ret ret
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align 2
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bs equ $
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psp equ bs + 0x200
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args equ psp + 0x80
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prog equ psp + 0x100
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