47 lines
703 B
PHP
47 lines
703 B
PHP
; reset segments
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rstseg mov ax, cs
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mov ds, ax
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mov es, ax
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ret
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; copy to far memory
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; IN es:bx far memory ptr (preserved)
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; ds:dx local ptr (preserved)
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; cx number of bytes to transfer
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; OUT cx set to zero
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; si & di trashed
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stofar mov si, dx
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mov di, bx
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rep movsb
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ret
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; copy from far memory
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; IN es:bx far memory ptr (preserved)
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; ds:dx local ptr (preserved)
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; cx number of bytes to copy
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; OUT cx set to zero
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; si & di trashed
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lodfar call swpds
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mov si, bx
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mov di, dx
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rep movsb
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; exchange es and ds
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swpds push ds
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push es
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pop ds
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pop es
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ret
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; normalize ptr in ds:dx
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norm mov ax, ds
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mov cl, 4
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push dx
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ror dx, cl
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and dh, 0xF
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add ax, dx
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mov ds, ax
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pop dx
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and dx, 0xF
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ret
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