Passthru printing oftern spews garbage to terminal in SCO OpenServer 5.0.5

I have a client with an SCO OpenServer 5.0.5 and an Acceleport PC/16e ISA board which has been installed for several years. The MPI version is 3.2.1.

This system has had a problem the entire time with passthru printing which I never could resolve and thus have eliminated it accept for an HP LaserJet 1100 on a Dorio 25 terminal in SCO Ansi emulation mode.

Occasionally, perhaps 2-3 times monthly, sending a print job to the terminal printer causes garbage to appear on the terminal and it stays that way until the processes running on it are killed and the getty is spawned, at which point it returns to normal.

This has always appeared to be a bug to me as opposed to an incorrect setting. Any light that could be shed on this issue would be GREATLY appreciated! I am wondering of there is a setting that can be changed, or if upgrading to MPI version 4.2.0 would solve the problem. I am planning to upgrade the MPI next week, but only to resolve this issue, and if I’d be wasting my time I’d rather not do it. For the record, here are the current ditty settings for the terminal/printer in question. I have played with the settings over time but have never been able to eliminate the problem:

ditty -a < /dev/pri1h

onstr \033[5i offstr \033[4i term ansi
maxcps 900 maxchar 100 bufsize 900 edelay 100
-forcedcd fastcook -altpin -fastbaud (38400) printer
eia232 -rtspace -dtrpace -ctspace -dsrpace -dcdpace
startc = 0x11 stopc = 0x13
-aixon astartc = 0x0 astopc = 0x0
-2200flow -2200print
speed 9600 baud; ispeed 9600 baud; ospeed 9600 baud; line = 0(tty);
intr = DEL; quit = ^; erase = ^H; kill = ^U; eof = ^D; eol = ^@;
swtch = ; susp = ; start = ^Q; stop = ^S;
-parenb -parodd cs8 -cstopb hupcl cread -clocal -loblk
-ortsfl -ctsflow -rtsflow
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -iuclc
-ixon -ixany -ixoff
-isig -icanon min = 4 time = 0 -xcase -echo -echoe -echok -echonl -noflsh
-iexten -tostop -xclude
opost -olcuc onlcr -ocrnl -onocr -onlret -ofill -ofdel

Thanks if you can help!

Try doing a “ditty -a” on the port again once the problem happens. Do any of the parameters (particularly the baud rate) change between the ditty -a you did above and when the problem occurs? If so, its more than likely embedded stty parameters in your printer interface.

BTW: MPI 4.2.0 will not support PC/16e (obsolete) products, so upgrading is not an option.