You don't want to know how many questions I started to type into
this email, then removed because I figured them out.  :-)

After using some of the things Bill wrote in the message quoted
below (the last obstacle was figuring out how :ms=: in printcap
worked) and rewriting some of my code several times, I now have 
a working StyleWriter I driver under NetBSD.  (Well, at least
I can print man pages on it with "groff -man foo.1 |lpr -Pstylps",
and the file "escher.ps" from the gs262 distribution comes out OK.)

Once I've had a chance to clean up the code a bit and write some
documentation, I'll make this available for general consumption.
In the meantime, if you have a StyleWriter I and a NetBSD-mac68k
machine with ghostscript installed and want to alpha-test this thing,
drop me a line.  If you have some other flavor of StyleWriter, you're
probably out of luck, but you might give it a try.  (If anyone in the
area of Portland, OR, USA has a different StyleWriter they could part 
with for a couple of days, it just might get support as well... ;)

At 9:19 PM 2/6/96, Bill Studenmund wrote:
>[Discussion of partial success w/ StyleWriter deleted]
>> - Is there an example of another gs driver that needs _two-way_
>> 	communication with the printer?  (The serial protocols the 
>> 	StyleWriter uses are STRANGE.  No flow control is the least
>> 	of it.)
>
>I think that you should just be generating an output file in gs.
>Set the system up so you use indirect queuing; the gs output
>goes into another queue. Make the second queue use an input
>filter that understands the weird handshaking of the printer.
>This way, you can also dump a large file of text, or graphics
>from a different computer, to the printer w/o problem. So
>the gs driver would not add the handshaking-request commands;
>the filter would.

The setup you describe here works, but is rather disk-space
intensive.  Since I want to image each page at printer
resolution (360dpi), the files that get put in the queue are
about 1.2 Meg per page.  I was able to create a lpr input filter
from a shell script that pipes the output from gs to my driver 
program, so that the pbm file never actually gets saved to disk.
I then set up /etc/printcap to use this filter so that PostScript
files get spooled properly.  It all seems to work pretty well.

Also, since the low-level printer driver will ONLY grok pbmraw
files, and always prints them at 360 dpi, putting things in its
queue is probably less than useful.  :-)  (The reason I did this is
that (AFAICT) the StyleWriter has no built-in fonts or ascii text 
capability at all.  Pbmraw seemed like the easiest of ghostscript's
raster output file formats to write input routines for, so...)

-- monroe