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From: iglesias.uci@Rand-Relay@sri-unix.UUCP
Newsgroups: net.micro.pc
Subject: BIOS Comm. Interupt Problem
Message-ID: <5453@sri-arpa.UUCP>
Date: Tue, 13-Sep-83 11:32:47 EDT
Article-I.D.: sri-arpa.5453
Posted: Tue Sep 13 11:32:47 1983
Date-Received: Sun, 18-Sep-83 21:58:17 EDT
Lines: 28

From:  Mike Iglesias <iglesias.uci@Rand-Relay>

I had problems running KERMIT on an XT with DOS 2.0.  It appears that
KERMIT is sending the first character (^A) repeatedly.  I traced the
problem to the following code (the dashed lines are mine):

outchr: mov al,ah               ; Char must be in al.
	mov cx,0
	call dopar		; Set parity appropriately.     [10]
outch1: mov ah,1                ; Output it.
	mov dx,0
        int comm
;-------------------------------------------------
	cmp ah,00H
	je outch3
	loop outch1
	 jmp r
;-------------------------------------------------
outch3:	jmp rskp

I ran KERMIT with the debugger and found that after the 'int comm',
ah was non-zero.  Looking at the BIOS listing for the XT, ah has the
status of the line unless the character couldn't be sent, in which case
bit 7 is set in ah.  If I remove the code between the dashed lines,
it seems to work.  To all you XT wizards out there:  what code should
be between the dashed lines to make it run properly on an XT?

Thanks for any help you can provide.