Subject: Re: DeskWriter (was Re: printer / modem)
To: Bill Studenmund <wrstuden@loki.stanford.edu>
From: John Valdes <valdes@macavity.uchicago.edu>
List: port-mac68k
Date: 01/10/1997 21:26:58
Bill Studenmund writes:

> > I've been using my DeskWriter (original model) connected to the
> > printer port w/ gs.  For the most part, it works OK, except it
> > occasionally will print garbage characters.
> 
> Are you using my gs binary? If not, the standard 500 support can send
> out garbage to a original model DW (basically the 500 supports an
> extra graphics mode that is unrecognized on the DW).

No, I'm using a copy I've compiled (gs 2.6.2) w/ the djet500 driver.
I thought that the problem might have been the PCL generated by this
driver, but as I mentioned, the identical PCL file sent to the printer
from the MacOS side (using ZTerm) prints just fine.  Additionally,
I've been using the djet500 driver w/ my MacOS version of gs 2.6.2 w/o
any problem for some time.

Nevertheless, I'll try your gs binary to see if it helps.  I believe
you've hacked George Cameron's deskjet driver (cdj*) for proper
monochrome output for the DeskWriter, and I like the grayscale
generated by that driver better than the djet500's anyway...
I notice that the 'ms=' setting in your printcap file are a little
different than mine; I'll try yours and see if that helps.

> It sounds more like you're getting a random character error once in
> every few files.  I've seen such a thing (one page in 20 had an error),
> but only rarely. I can't think of the error in the driver.

It seems to depends on the amount of data on the page, but for the most
part, I get about 5-10 errors per page.  It could be though that the
smaller files which print w/o errors just don't have the same byte
stream(s) which generate the error(s).  I haven't tried a large ASCII
file (greater than the DeskWriter's 8K(?) buffer) yet.

> > As a test, I converted the tiger.ps sample file that comes with gs to
> > PCL using gs, and send it to the printer using:
> > 
> >   prompt# ( stty 57600 raw -clocal cs8 -parenb -cstopb -echoctl \
> >            crtscts mdmbuf ; cat tiger.pcl ) < /dev/tty01 > /dev/tty01
>
> Try stty w/o the mdmbuf. Under 1.2, that puts you into a mode where
> DTR is used as the input flow control (RTS on normal serial ports).

I've tried it w/o mdmbuf as well, but with the same results.  The
DeskWriter manual says that it uses DTR for input flow control, so
whatever setting causes netbsd to monitor the line to which the
DeskWriter's DTR is connected is the one I'd want to use.

> How often do you see the error?

See above.

Thanks for the suggestions.  Any other ideas?

John