Date   : Wed, 27 May 1987 16:53:51 GMT
From   : beta!dzzr@nyu.arpa (Douglas J Roberts)
Subject: Fix to a bug in Lifeboat CP/M 2.2 printer driver

Since I've been pestering this group recently for help, I thought
that I'd share the solution now that I've found it.

The parallel port driver was sending garbage to my printer, so
after I located the problem I modified the Horizon user area and patched
it in. For those of you interested, here is the offending code and the
fix.


COUT2:
       ;Parallel port output.
       IN      6               ;Motherboard status
       ANI     1
       JZ      COUT2   
       MVI     A,20H           ;Reset PO flag
       OUT     6               ;Output char
       MOV     A,C             ;Load accumulator
TIN1:
       ORI     80H             ;Set strove false <-- REMOVE THIS LINE!!!
       OUT     0               ;and send character
       XRI     80H             ;Toggle strobe
       OUT     0               ;Output
       XRI     80H             ;and toggle again
       OUT     0
       ANI     7FH             ;Mask to ASCII
       RET

The indicated line was setting the high bit on each character,
effectively putting my Epson MX-80 into graphics mode.

Thanks again for all the help!

--Doug