laser-lovers@uw-beaver (07/17/85)
From: Neal Holtz <holtz%cascade.carleton.cdn%ubc.csnet@csnet-relay.arpa>
I have a strange problem downloading raster images to a LaserWriter.
Things work just fine in interactive mode (i.e., after "executive"),
but when I send exactly the same data in server mode (over 9600 baud
serial) all PostScript commands seem to be executed, the hex data seems to be
read properly (I put in some print statements to echo it), but the output
page is blank!
------------------ Details:
The input raster data looks like:
/width 80 def
/depth 80 def
printimage
FFFFFFFFFFFFFFFFFFFF
FFFFFFFFFFFFFFFFFFFF
60000000000000000FFF
... (76 more lines in here)
7AB77FDDBB76EDDBBFFF
showpage
'printimage' opens an input file, allocates a string large enough to hold one
scan line, sets up a few graphics paramaters, then executes the 'image' operator.
The procedure argument to 'image' is 'readscanline', shown here in its entirety:
/readscanline
{ infile scanline readhexstring pop % input scanline is left on stack
dup outfile exch writehexstring (\n) print % this line added for debugging
} def
Finally, 'infile' is a file object opened thus:
/infile (%stdin) (r) file def
------------------
The debugging line added to 'readscanline' shows that the input is read O.K.,
and the 'showpage' operator at the end of the input is executed.
Help!!!