[comp.lang.postscript] Parallel PS interface experience/problems

amichiel@rodan.acs.syr.edu (Allen J Michielsen) (12/17/90)

   I have a bunch of HP (IIP's & III's) with extra memory and HP/Adobe
PostScript Cartridges.  While I am exceedingly happy with them in general,
and even more so when using the appletalk interface & a MAC.  I do seem to
have a strange reoccuring problem.  When I'm using the parallel printer 
interface on a PS, generally from inside a application (WP), AND I'm 
generating a complex page (several graphics windows, and several fonts,
equations, etc.) the output tends to have a nasty habit of randomly losing
items (lines, figures, shapes, fills, etc) from the graphics windows, &/or
pasted/lined-up parts of equations become 'un-aligned'.  If I 'print' the
same thing to disk, then 'print' that file, the output is fine, & when I
print just the graphics page alone, the output is fine.  Nothing on the page 
is getting or being 'cropped' like that which occurs when the laserwriter
runs out of memory and starts moving the margins in to conserve.  The 
size and complexity of every page (8.5x14" nearly 0 margins-- camera ready
publication output) is such that NO page can print on a apple laserwriter,
plus or IINT, without getting cropped.  The HP's have 3 MB of ram, and
I'm trying to diagnose properly the exact and total cause of the problem.
   I figure it's most likely that either the HP is getting caught at the
beginging of a memory shortage (*but amd surprised that no margin cutting
is taking place*), OR that there's some 'soft' problem with the software
recognizing the flow control of the parallel port in time.  However, HOW I
will exactly identify the cause is kinda a mystery to me.  I feel that printing
a single page fine, and dos printing the output file (outside the application)
are both indicators that the problem is application bound I/O difficulty.
But wonder if there MAY be some interaction with memory & status I/O.  I'm
thinking of trying to use the serial port & see what happens there, and also
trying to find a application compatible printer spooler (in software) & see
what happens then.  Somehow, a little voice in the back of my mind keeps coming
back to a 'problem' that more available memory will make disappear....
   Any ideas ???
al



-- 
Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University
 InterNet: amichiel@rodan.acs.syr.edu  amichiel@sunrise.acs.syr.edu
 Bitnet: AMICHIEL@SUNRISE 

tj@gpu.utcs.utoronto.ca (Terry Jones) (12/19/90)

Just as a test take that same WordPerfect page and instead of printing
to Port LPT1: set it to print to a dos file called LPT1

This results in WP thinking it is writing a disk file and dos
saying this disk file is a magic name send it out the port. The
result is that WP does not write directly to the hardware.
If this then prints correctly then I would blame WP for the problem.

Some of the newer versions of WP 5.1 (yes virginia there are a million
different 5.1 versions roaming around...) have an option on the printer
setup that says Print direct to hardware yes/no? or something to that
effect. Saying Yes can give better speed according to WP. Saying no
I suspect makes things work properly on some machines where the
hardware is "exactly the same as IBM... except..."

tj

P.S. Let me know the results...