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Re: How Should I document Printing a DHGR image on an Apple II?

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In article <m2ddsc$nbe$1@speranza.aioe.org>,
Bill Buckels <bbuckels@mts.net> wrote:
>I want to document printing a DHGR image from an Apple IIe on an ImageWriter 
>using a Super Serial Card in a cc65 program.
>
>Has this code been done already and if so can someone point me to it for 
>review?
>
>If it hasn't been done in cc65 has it been done in AppleSoft BASIC? That 
>code would get me started. Otherwise if this has never been done before I 
>will be the first... this is unlikely so someone should have this code 
>somewhere I think.

Pure BASIC code won't work.  You need to send 8-bit data to the printer, but
you can't do that without at least a little stub assembly-language
routine similar to this:

0300: A9 A0     LDA #$A0
0302: 4C ED FD  JMP COUT 

The bigger stumbling block is that the pixels on the HR and DHR screens are
grouped horizontally, but need to be grouped vertically for printing.  BASIC
would be intolerably slow at this sort of bit-mangling.  C would've been
better, but I didn't have a compiler for the Apple II and didn't even start
learning that language until maybe my second year of college (introductory
computer science courses were still using Pascal at the time).

I had a go at it with assembly language back in the day.  I'm pretty sure I
had some working code at one point, but if I still have it, it's probably
packed up in the garage.  I don't recall if it was Hi-Res or DHR; if it was
only Hi-Res, it wouldn't have been that big a deal to adapt to DHR: print at
160x72 dpi instead of 80x72, and alternate between auxiliary and main memory
for each group of 7 columns of pixels.

At one point, I was trying to push the Imagewriter for all it was worth.  I
had a driver (usable from BASIC) that did two-pass printing of text at
160x144 dpi to emulate other printers' "NLQ" mode.  At one point, I was
trying to print color graphics in multiple passes by printing a pass in one
color, winding the paper back, swapping ribbons, and printing the next pass. 
Quality wasn't particularly good, in part because while I could find yellow
ribbons for the Imagewriter, I couldn't find cyan and magenta.  Blue and red
were available, but produced too-dark print.  Seeing how proper color
dot-matrix printers handled printing photos and such a few years later, I
shouldn't have gotten my hopes up too high.  For monochrome images, though,
it worked well enough.

  _/_
 / v \ Scott Alfter (remove the obvious to send mail)
(IIGS( http://alfter.us/            Top-posting!
 \_^_/                              >What's the most annoying thing on Usenet?

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Thread

How Should I document Printing a DHGR image on an Apple II? "Bill Buckels" <bbuckels@mts.net> - 2014-10-24 06:40 -0500
  Re: How Should I document Printing a DHGR image on an Apple II? scott@alfter.diespammersdie.us (Scott Alfter) - 2014-10-24 17:04 +0000
    Re: How Should I document Printing a DHGR image on an Apple II? "Bill Buckels" <bbuckels@mts.net> - 2014-10-25 05:26 -0500
      Re: How Should I document Printing a DHGR image on an Apple II? scott@alfter.diespammersdie.us (Scott Alfter) - 2014-10-28 18:16 +0000
      Re: How Should I document Printing a DHGR image on an Apple II? scott@alfter.diespammersdie.us (Scott Alfter) - 2014-10-28 19:37 +0000
  Re: How Should I document Printing a DHGR image on an Apple II? "Christopher G. Mason" <cgm1@my-deja.com> - 2014-10-24 17:19 -0400
  Re: How Should I document Printing a DHGR image on an Apple II? "Bill Buckels" <bbuckels@mts.net> - 2014-10-24 19:43 -0500
    Re: How Should I document Printing a DHGR image on an Apple II? Steve Nickolas <usotsuki@buric.co> - 2014-10-25 02:30 +0000
    Re: How Should I document Printing a DHGR image on an Apple II? "Christopher G. Mason" <cgm1@my-deja.com> - 2014-10-24 23:01 -0400
      Re: How Should I document Printing a DHGR image on an Apple II? "Bill Buckels" <bbuckels@mts.net> - 2014-10-25 05:12 -0500
      Re: How Should I document Printing a DHGR image on an Apple II? scott@alfter.diespammersdie.us (Scott Alfter) - 2014-10-28 19:20 +0000
        Re: How Should I document Printing a DHGR image on an Apple II? "Bill Buckels" <bbuckels@mts.net> - 2014-10-28 16:24 -0500
    Re: How Should I document Printing a DHGR image on an Apple II? gids.rs@sasktel.net - 2014-10-24 21:15 -0700

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