Actually, now that I'm looking really, really closely, I can see some
extremely minor variations on the red and blue channels. I definitely
can't see the difference on green, though it may well be the less-than-
brilliant signal I'm getting.
If you can be bothered taking the time, this is what my Sam is doing:
http://members.allegro.cc/ThomasHarte/temp/Kaleidoscope1.mp4 (about
8.2 mb)
http://members.allegro.cc/ThomasHarte/temp/Kaleidoscope2.mp4 (about
8.3 mb)
Is that really all that it is meant to do?
On 9 Apr 2008, at 20:19, Colin Piggot wrote:
Thomas Harte wrote:
1) should the Kaleidoscope be a box that contains four ICs
(t74ls20b1,
gd74ls374, gd74ls14, t74ls133b1), some resistors and capacitors and
about half a board of empty space with gaps for other chips and
stuff?
Yes, that's the Kaleidoscope. It's a half built 'hardware
development kit',
but in the standard mgt/samco interface box instead of a bare PCB.
2) should the Kaleidoscope function correctly across a composite
video
output drawn from the Sam's scart port?
Yes. The Kaleidoscope changes the red/green/blue voltage levels,
which in
turn feed the MC1377 Composite Video generator. The subtle changes the
Kaleidoscope make will be seen no matter what video signal you use -
RGB,
Comp. Vid or UHF.
My problem is that having identified which box must be
the Kaleidoscope by deduction, the bundled software does
absolutely nothing. So, questions:
Well, there should be some very, very subtle changes, but that's it.
The
Kaleidoscope is useless, I 'reviewed' it in detail in SAM Revival 15
looking
at software for it (I only found one piece of software other than the
bundled disk that used it!) and gave it somewhat of a slagging!
To cut and paste what I've said on the list before:
"It was a complete bodge.
What the kaleidoscope did was pull down the RGB video signals
generated by
the SAM as normal (by darkening the output by varying amounts of
red, green,
blue - set with an OUT command to the kaleidoscope port) so it
technically
produced 256 tinted shades of the original colours - in total 32768
shades,
but could they be used in a proper fashion - nope!
So whatever value of shading the kaleidoscope was set to would
affect all
the colours on screen. There was no real way to use it all, could
you have
individually shaded pixels - nope again! At most, you could write
code to
tint horizontal groups of 16 pixels at a time… but for all 192
scanlines you
would be using all the CPU time and even effectively tinting 16
pixel blocks
that wouldn’t really let you achieve any decent graphical effects,
plus 62%
of all the CPU time is being used. In all, a waste of time, it
couldnt be
utilised in any useable way at all, therefore no software attempted
to used
it."
So really, don't waste your time with it, the claims of it allowing
the SAM
to have a 2048 colour art package etc... utter rubbish :)
Colin
======
Quazar : Hardware, Software, Spares and Repairs for the Sam Coupe
1995-2008 - Celebrating 14 Years of developing for the Sam Coupe
Website: http://www.samcoupe.com/
