[comp.sys.apple] VOC 400 line graphics

johnmac@fawlty.towers.oz (John MacLean) (12/28/89)

OK, I have 400 line graphics - but the plot thickens.
If you have a VOC in slot 3, try this:
$C029:C1
$C0B5:FF
$C0B9:FF
and you get 400 line graphics.

I have not determined which bits are actually needed yet, I only figured
this out last night.
As someone pointed out before, the flicker on a standard IIGS monitor is
really bad, although I have not yet loaded a real picture in, so it may
not be as bad as it first seems.

$C0B9 appears to be a duplicate of $C0B1. Most probably $C0B8-F map onto
$C0B0-7.

Now for the good bit - as I mentioned previously, there is a new strange
mode which mixes up the locations of the pixel map, the SCBs and the
color palettes.
I thought I had figured out how to force things back to standard, but
not so.
So what I have at the moment is 200 lines in bank $E1 of standard SHR,
and 200 lines of mixed up wierd SHR in bank $E0 interlaced.
Sometimes I manage to get standard SHR in both banks, but not always,
and certainly not guarenteed.
I have even managed to mix up the order of pixels/SCBs/palettes in
several different ways.
If anyone figures this out, let me know.
It is possible that none of this happens under program control, but
only through the monitor.

Tonight I will write a driver for The Graphic Exchange, and use my GIF
loader to load in some 400 line graphics.
I will post the results tomorrow.

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