[comp.sys.atari.st] More colors per screen.

cmcmanis%pepper@Sun.COM (Chuck McManis) (03/12/88)

In article <2508@tekig5.TEK.COM> wayneck@tekig5.TEK.COM (Wayne Knapp) writes:
> I found out that I computed the movm timing incorrectly...

I have been following this exposition quite closely, (way to go Wayne) 
partly because video is sort of a hobby of mine and partly because it
reminds me of programming 8 bit machines where one had to go through 
such gyrations as touching every row address to keep the DRAMs refreshed
or not using instructions with an odd number of clocks because it would
throw off the video timing. So the stuff about changing color palletes
on the fly are fun to watch. However, (and you knew this was coming didn't
you?) you will notice that as Wayne's algorithims get ever more complex
they use up more and more of the available CPU cycles! One goal is to have
something that your program can call to display a picture, but your
program won't be able to do anything while it is being displayed. :-(. 

A couple of solutions have come to mind, one would be to buy a second ST
and have it display the images while the main one did the rendering. The
other would be to add a different frame buffer logic to the motherboard 
and then work on poking GEM into using it correctly. Maybe the EGA chip
set that Atari is using in the Atari-PC could be used here. Spectrum 512
is an impressive program, is there anything like Spectrum Paint? Something
that would allow designing these multicolor images?

On a less statisfactory note, consider the following tidbits of information.
Atari pushes the ABAQ as the answer to small workstations and then figures
its price will be very high because the cost of getting the Transputer chips.
Inmos, manufacturer of the Transputer had been (and still was at the time)
for sale at damn near firesale prices. The holding company was not sure they
could survive as an independent semiconductor company. Atari *didn't* buy
them, although they probably could have, I never even heard that they were
even trying. Now for a company that could really use some in house 
semiconductor fab capability, this looked like an ideal match. Hell, Inmos
could have made blitters as well! So, from the outside looking in (always
a tough position) it looks like Atari threw the ABAQ up as a weather
ballon to see how many people would send them $100 and thus check the 
feasibility of marketing it. And the results of that test were "not enough"
so they didn't bother assuring their supply of Transputers. (Inmos could
as easily go out of business and leave them high and dry). Ah well, I have
now moved my expections for the ABAQ from late '88 to early '92. I wonder
why they don't use the ARM chip if they don't mind going with a different
architecture.

--Chuck McManis
uucp: {anywhere}!sun!cmcmanis   BIX: cmcmanis  ARPAnet: cmcmanis@sun.com
These opinions are my own and no one elses, but you knew that didn't you.