[comp.sys.ibm.pc.misc] PC --> LaserWriter IInt via serial ports?

zeno@athena.mit.edu (R. Duffy) (06/27/91)

[Sorry if this is a duplicate posting.]


A colleague of mine has an IBM AT running DOS 3.2 and an Apple LaserWriter
IInt.  The AT has a Tops "Flash Card" installed with NetPrint set up to
spool print jobs to the printer.  For various reasons we think it would be a
lot better to just connect the printer directly and not bother with
networking/spooling (there's no LAN involved).

According to the LaserWriter manual, one can just connect a serial port on
the PC to the printer's serial port, set the two printer switches to Up,
Down (respectively), and that should do it.  I tried this using each of the
AT's two serial ports.  We can copy a Postscript file to the corresponding
COM_, but nothing prints.  The only things I did to disable the Tops stuff
were to remove its device driver from config.sys, and disable the "topspap"
and "netprint" programs which were run in the autoexec.bat.  The Tops card
was not cabled to anything.  There are no other memory-resident utilities.
DOS never gave a "not-ready" error, and I know that the two ports both work
because I connected each one to a modem and successfully used them for
communications.  Similarly I tried switching cables, and they both work for
the phone connection.  They're just ordinary 9-to-25 pin serial cables.  I
tried both no parity and even parity on both ports.  I've also tried the
manual's Postscript program for switching between the XON/XOFF and EXT/ACK
protocols (by just copying it to COM_), but still no printer output, even
though it says "1 file(s) copied".

Any ideas?  Could the Tops card be interfering even though it's not cabled to
anything and I'm not running any of its software?

E-mail preferred.  Thanks very much.



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