Altos/Xenix problem - help requested

[tm at laidbak.UUCP]

The following is a problem of a friend overseas. His system is
XENIX version 3.3aSO and runs on an Altos 2086. Everything seemed to be
working fine until they hooked up a CDC 9335-2 printer to the parallel port.
The problem occurs intermittently, under various conditions:
printing single page documents, multi-page documents, and regardless of the
program used to print. The following appear in the console:

lp: cannot get a page
lp: cannot get a page
lp: cannot get a page
	...
TRAP 000D IN SYSTEM

ax=FFFE bx=FFFE cx=0028 dx=0128
si=7FFF di=0001 bp=0380
fi=0206 uds=0018 es=0128
pc=0020:B39C ksp=036A

The lp log file /usr/spool/lpd/LOGFILE contains then messages:

TIME AND DATE OF CRASH	WHAT HAPPENED	       DEVICE	        WHO DID IT
Mon Nov 24 1:35:11:lpd:Cannot reopen stdin as /dev/lp 0 bytes printer joe

The local CDC people have made a cable of their own to connect the printer to
Altos, and they suspect that this might be the problem.
It seems obvious that these panic messages come out of the lp device driver,
but they do not have the sources and cannot verify it.
Does any kind soul outa there know the real cause and what happens?
Could it be something like a bad connection in the cable?
Could somebody please give me info on how to get in touch with Altos to buy
the original cable of Altos, just in case?
Any help greatly appreciated.

	-Takis Mercouris
	ihnp4!laidbak!tm