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Technotools
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Technotools (Chestnut CD-ROM)(1993).ISO
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lang_c
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mikecom
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txfree.asm
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Assembly Source File
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1987-05-15
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875b
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28 lines
title GET FREE SPACE IN TRANSMIT BUFFER
include subfx.h
; Mike Dumdei, 6 Holly Lane, Texarkana TX 75503
;****************************************************************************
; ASYNC_TXFREE -- Returns number bytes left available in the transmit buffer
; or R_NOPORT if comm port arg was not valid.
;****************************************************************************
begseg COMM_TEXT
publicproc _async_txfree
push bp
mov bp,sp
push si ;C stck frame, save regs
call __ck_port_arg
jz free_exit ;exit if bad port nbr
mov ax,TX_FREE ;get bytes available
free_exit:
pop si
pop bp
ret ;restore regs and exit
_async_txfree endp
endseg COMM_TEXT
end