[comp.sys.sun] NEC LC890 problems

frank@ames.arc.nasa.gov (Frank Gorishek) (08/22/89)

In sun-spots v8i92, joe@islsun5.mse.lehigh.edu (Joe Sieczkowski) writes:

| I was never able to get XON/XOFF to work proberly with my NEC LC 890
| PostScript printer.  I'm running Sun version 3.5.  It seems like the sun
| never sees the ^S from the printer.  My final solution was to set the
| printer at 1200 baud .... ie spoon feed it.
| 
...
| 
| If I even think about increasing the baud rate to 9600...the printer
| looses output.  If anyone out there knows a solution to this I would
| appreciate it.

We had the same type of problem here.  As it turns out the LC890 doesn't
drive "true RS232" (i.e., it drive +/- 5volts NOT +/- 12volts).  The
serial port on the sun just can't see anything the LC890 sends out.  We
replaced the printer, however there are such things as TTL/RS232
converters.

--frank

-- 
Frank Gorishek
frank@AMD.COM
512-462-4117 or 800-531-5202 x54117

mark@drd.Com (Mark Lawrence) (09/16/89)

} In sun-spots v8i92, joe@islsun5.mse.lehigh.edu (Joe Sieczkowski) writes:
} | I was never able to get XON/XOFF to work proberly with my NEC LC 890
} | PostScript printer.  [...]

amdcad!cayman!frank@ames.arc.nasa.gov (Frank Gorishek) wrote:
} X-Sun-Spots-Digest: Volume 8, Issue 103, message 11 of 14
  [about how to raise the line level voltages so that the computer
  would *see* the crummy XOFF's]

The way we fixed it was to buy a serial/parallel convertor buffer
box that you can buy at any PC store for ~US$100.  We hooked it up
at 9600 bps to the Sun configured to do XON/XOFF and hooked it up
parallel to the printer.  Everything works _reliably_.   I've been
pretty happy with the `ol brick outhouse (as somebody once described
the '890) since we did all this.

Take heart, things _do_ get better with SunOS 4.x as far as describing 
the modes you want on the serial line in your printcap.

   mark@DRD.Com                (918) 743-3013              Jer. 9:23,24
   {uunet,rutgers}!drd!mark