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Rev 1849 Rev 1851
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int 0x21
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int 0x21
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; if all went well, jump back to start
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; if all went well, jump back to start
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jnc skipsig
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jnc skipsig
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; save error code into cl
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mov cl, al
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; display program name (in DS:DX), but first replace its nul terminator by a $
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mov si, dx
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PARSENEXTBYTE:
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lodsb ; load byte at DS:SI into AL and inc SI (direction flag is clear already)
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test al, al  ; is zero yet?
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jnz PARSENEXTBYTE
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mov [si], byte '$'   ; replace the nul terminator by a $ and display it
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mov ah, 0x09
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int 0x21
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mov [si], byte 0     ; revert the nul terminator back to its place
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; restore DS=CS
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; restore DS=CS
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mov bx, cs
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mov bx, cs
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mov ds, bx
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mov ds, bx
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; update error string so it contains the error number
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; update error string so it contains the error number
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add al, '0'
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mov al, '0'
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add al, cl    ; the exec error code
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mov [ERRLOAD + 4], al
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mov [ERRLOAD + 6], al
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; display error message
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; display error message
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mov ah, 0x09
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mov ah, 0x09
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mov dx, ERRLOAD
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mov dx, ERRLOAD
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int 0x21
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int 0x21
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; terminated with \r) - a single 0x0A byte is passed so SvarCOM knows it is
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; terminated with \r) - a single 0x0A byte is passed so SvarCOM knows it is
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; called as respawn (as opposed to being invoked as a normal application)
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; called as respawn (as opposed to being invoked as a normal application)
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; this allows multiple copies of SvarCOM to stack upon each other.
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; this allows multiple copies of SvarCOM to stack upon each other.
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CMDTAIL db 0x01, 0x0A, 0x0D
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CMDTAIL db 0x01, 0x0A, 0x0D
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ERRLOAD db "ERR x, FAILED TO LOAD COMMAND.COM", 13, 10, '$'
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ERRLOAD db ": ERR x, LOAD FAILED", 0x0A, 0x0D, '$'
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; variables used to revert stdin/stdout to their initial state
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; variables used to revert stdin/stdout to their initial state
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OLD_STDOUT dw 0xffff
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OLD_STDOUT dw 0xffff
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OLD_STDIN  dw 0xffff
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OLD_STDIN  dw 0xffff
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