Bug Fix for screen prints on Epson-like printers

James E. Prior jep at oink.UUCP
Mon Mar 4 05:31:57 AEST 1991


I hacked a patch into the screen print program that prints a copy of the 
screen pixel by pixel.  The patch corrects the line spacing.

As the screen printing is done in graphics mode, the line feeds need to 
advance the paper 8/72" instead of the normal 1/6".  As distributed, 
the sprint program does this too late.  It doesn't change the line 
spacing until _after_ the graphics printing.  This causes the first 
screen print to have horizontal gaps, and subsequent text printing to 
be scrunched vertically.  

My hack implements the 8/72" line spacing at the beginning of the 
graphics printing, and set the line spacing to 1/6" after the screen 
print.  

I changed four bytes in the /usr/bin/sprint program.  What follows are 
a single line of the hex dump of the new and old version, so that you 
can patch your own sprint.  

-rwxr-xr-x  1 bin     bin        9764 Mar  3 13:46 /usr/bin/sprint*
00002180  1B 4C D0 02 00 00 1B 41 08 1B 32 00 1B 33 24 00  >.LP....A..2..3$.<
address   data in hex                ^^ ^^       ^^ ^^      data in ASCII
                                     ^^ ^^       ^^ ^^

-rwxr-xr-x  1 bin     bin        9764 Jan  1  1970 /usr/bin/sprint.virgin*
00002180  1B 4C D0 02 00 00 1B 41 08 0D 00 00 1B 32 0D 00  >.LP....A.....2..<

Caveats:

This patch works for by Okidata Microline 182i which is _supposed_ to be able 
to emulate Epson printers.  I have not tested the patch on an actual Epson 
printer.  It might be the case that the original sprint works fine on real
Epson printers.  If screen prints work on your machine, then don't mess 
with this patch.  In other words, if it ain't broke don't fix it.  

I'm using version 3.51 of the operating system.  You version of sprint may 
differ.  You may want to run the following sum commands and compare the 
output to the version of sprint that you have.  If your sums are different, 
then my patch might not apply.

sum /usr/bin/sprint*
51694 10 /usr/bin/sprint
51606 10 /usr/bin/sprint.virgin

sum -r /usr/bin/sprint*
42291    10 /usr/bin/sprint
19696    10 /usr/bin/sprint.virgin
-- 
Jim Prior    jep at oink    osu-cis!n8emr!oink!jep    N8KSM



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