[comp.sys.ibm.pc.hardware] printing via the serial port

SASDDI@vm.sas.com (05/17/91)

I wonder if some kind soul might help me with this; I'm rather new to
this.

I have a terminal (Control Concepts 3276, emulating the IBM terminal
of the same model) to which I have attached an Epson RX-80 printer
via a serial card (don't remember what kind).  Works great.

Now I have a PC (Leading Edge D) sitting beside it.  I would like to
hook the printer to an A/B switch so I can use it from the PC sometimes
and from the terminal othertimes.  But as far as I know (which obviously
isn't very far) a printer is expected to be hooked to a PC via the
parallel port.

Is there some way I can hook my printer to the serial port, and somehow
tell the PC and all the software on it that that's where it is?  (By
installing(writing!? :-( ) a device driver maybe?)  I don't think (but
I'm not 100% sure -of anything!-) that you can use the parallel port on
the printer with the serial card plugged in.  And it's way too much
trouble to swap the board in and out.

Thanks in advance for any help you can give me.

------------------------------------------------------------------------
Dale D. Ingold           SAS Institute Inc.      snoddi@mvs.sas.com
MVS Host Group           SAS Campus Drive        919/677-8000 x7603
                         Cary, NC  27513-2414

dlow@pollux.svale.hp.com (Danny Low) (05/18/91)

>Now I have a PC (Leading Edge D) sitting beside it.  I would like to
>hook the printer to an A/B switch so I can use it from the PC sometimes
>and from the terminal othertimes.  But as far as I know (which obviously
>isn't very far) a printer is expected to be hooked to a PC via the
>parallel port.

Just hook the printer to the serial port of your computer using
the switch box. This port is most likely COM1 unless you have a really 
screwy configuration. Use the mode command to set up COM1 as a printer 
and re-direct LPT1 to COM1. You may have to reconfigure your software 
to tell them the printer is now on COM1 and no longer on LPT1 but that 
should be it.

			   Danny Low
    "Question Authority and the Authorities will question You"
	   Valley of Hearts Delight, Silicon Valley
	     HP NPCD   dlow@pollux.svale.hp.com

SASDDI@vm.sas.com (05/21/91)

Many thanks to the following people for their responses:
   Galen Hekhuis         <gkh@krebbs.acc.virginia.edu>
   Chance C. Guerin      <guerin@cod.nosc.mil>
   Jonathan Miner        <jwm712@unhd.unh.edu>
   Pietro P. Rizzi       <pietro@mtecv2.itesm.mty.mx>
   Joe Dorner            <dorner@nprdc.navy.mil>
   James Birdsall        <jwbirdsa@amc.com>
   Jui-hsiang Allan Yang <yang-allan@cs.yale.edu>
   Louis Davidson        <louis@mthvax.cs.miami.edu>
   Rich Snow             <rich@aoa.utc.com>

They all pointed out that the DOS manual describes using

   MODE COM1:baud,parity,bits,stop-bits,P
and
   MODE LPT1=COM1

Unfortunately, it's not working.  The printer is set for 1200 baud,
even parity, and 2 stop-bits (not sure if it's 7 or 8 data bits).
So that's what I set the COM1 port to, then I issue the second MODE
command to redirect the printer, then I attempt to test it with

   ECHO hi > LPT1

Nothing.  The printer stays quiet, and the system locks up until I
hit CNTL-BREAK (that's if I added the P option; without it, after a
few seconds, the system complains about the port (or words to that
effect) and asks the ubiquitous question: Abort, Retry, Ignore?).

I did of course try several variations, particularly of the number
of data- and stop-bits.

One extra variable: to connect the printer to the PC, I had to borrow
a gender-mender from work. (The cable has two male plugs, as does the
PC's serial port.)  It's definitly NOT a null modem, as it's a ribbon
cable with connectors on either end; no place to cross the send/receive
lines.

Any more suggestions from you net.gurus and/or hackers? :-)

Thanks in advance.

------------------------------------------------------------------------=
Dale D. Ingold           SAS Institute Inc.      snoddi@mvs.sas.com
MVS Host Group           SAS Campus Drive        919/677-8000 x7603
                         Cary, NC  27513-2414

rhaar@albert.cs.gmr.com (Robert L. Haar CS50) (05/22/91)

(text deleted .....)
|> 
|>    MODE COM1:baud,parity,bits,stop-bits,P
|> and
|>    MODE LPT1=COM1
|> 
|> Unfortunately, it's not working.  The printer is set for 1200 baud,
|> even parity, and 2 stop-bits (not sure if it's 7 or 8 data bits).
|> So that's what I set the COM1 port to, then I issue the second MODE
|> command to redirect the printer, then I attempt to test it with
|> 
|>    ECHO hi > LPT1
|> 
|> Nothing.  The printer stays quiet, and the system locks up until I
|> hit CNTL-BREAK (that's if I added the P option; without it, after a
|> few seconds, the system complains about the port (or words to that

Which port? - COM1 ? What is the error message?

|> effect) and asks the ubiquitous question: Abort, Retry, Ignore?).
|> 
|> One extra variable: to connect the printer to the PC, I had to borrow
|> a gender-mender from work. (The cable has two male plugs, as does the
|> PC's serial port.)  It's definitly NOT a null modem, as it's a ribbon
|> cable with connectors on either end; no place to cross the send/receive
|> lines.

You may well need a null modem. It sounds to me like you did
everything right. 

You might want to get your hands on an RS232 "breakout" box
with monitor lights for Tx and RX data and for the hardware
flow control lines (DTR, DCR, RI, etc.)

    	Bob Haar  InterNet : rhaar@gmr.com 
	Computer Science Dept., G.M. Research Laboratories
DISCLAIMER: Unless indicated otherwise, everything in this note is
personal opinion, not an official statement of General Motors Corp.

doug@giaea.gi.oz (Douglas Thomson) (05/22/91)

In article <91141.093332SASDDI@vm.sas.com> SASDDI@vm.sas.com writes:
>One extra variable: to connect the printer to the PC, I had to borrow
>a gender-mender from work. (The cable has two male plugs, as does the
>PC's serial port.)  It's definitly NOT a null modem, as it's a ribbon
>cable with connectors on either end; no place to cross the send/receive
>lines.
>
>Any more suggestions from you net.gurus and/or hackers? :-)

To connect our PCs to an EPSON LQ400 serial printer, we were told to use
the following cable connections:
    PC end             PRINTER end
    2 ---------------- 3

    3 ---------------- 2

    6 --+
        |
    8 --+------------- 5
        |
    20 -+

    7 ---------------- 7

    5 ---------------- 20

Doug.
(doug@giaea.oz.au)
...!munnari!goanna!giaea!doug