U12570@UICVM.UIC.EDU ("Edward A. Garay") (10/20/89)
Does anyone on the list know of a problem with the LaserWriter NTX
using XON/XOFF handshaking for serial asynchronous communications?
We recently connected this printer to our mainframe for our Publications
department, and we are experimenting some random hang-ups. It works
about 70% of the time, but sometimes it just hangs there while the
host is waiting for an XON to send more PostScript to it.
The mainframe is an IBM 3081 running VM with RSCS as the spooling
system. RSCS has an ASCII line driver that talks to a dedicated
port on an IBM 7171 controller. Out of the 7171, comes serial
data to a Sytek modem, then to the Sytek network, and then to
another modem next to the printer.
Needless to say, we have verified proper configuration and
communications to the modem next to the printer.
Publications staff tell me that they had experienced similar
problems in the past when the LaserWriter NTX was directly
connected to a PC in asynchronous mode using XON/XOFF.
They say they have heard of problems using the LaserWriter
with the XON/XOFF handshake, and that Apple is looking into it.
I know the original LaserWriter's serial interface had its problems,
but I suspect these were corrected on the IINTX. Besides, Apple's
LaserWriter II NT/NTX Owner's Guide documents that it should work.
Thanks in advance for any information or help that you can
provide on this matter.
--- Ed Garay
University of Illinois at Chicago
Bitnet: U12570@UICVM
Internet: U12570@UICVM.UIC.EDU