Re: Sprite card?

[anoneds@netscape.net (Ben Yates)]

Ernest <leucoplast@seanet.NOSPAM.com> wrote in message news:<srECb.380792$275.1230943@attbi_s53>...
> What does a Sprite video card do?
> 
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2772834489&category=4610

That _particular_ model has a TMS9918A VDP, the same used in the
TI-99/4A and MSX-1 computers.
Modes:
Graphics-1: 32x24, 768 character position, 256 characters (definable).
Characters divided into 32 character sets (8 each). Each set has a
foreground/background color (2 colors per set), out of the 16
available colors.
Text: 40x24, two color (out of 16).
Multicolor: 64x48 low-res blocks, each being one of 16 colors.
Graphics-2: Like Graphics-1, but 768 characters definable. Each
character is given a foreground/background color for each pixel line
of the character. This is the "bitmap" or high-res mode.
Various other undocumented modes.

Sprites are available in all modes except Text. There are 32 sprites,
with a foreground color (out of 16).
Four magnifications:
1 : single-size, one character cell sprite (8x8)
2 : single-size magnified - same as 1, but twice the size
3 : double-size - 4 character cells (16x16)
4 : double-size, magnified - same as 3, twice the size.

Sprites have priority - sprite 1 passes over sprite 2. Only four
sprites allowed per horizontal line, higher ones "disappear".

The TMS9918A allows an external video signal for the backplane. A
feature I would love to play with, but it requires external
synchronization.

I had a magazine detailing a hardware/software combo that used a card
with the same chip to add sprites to the Apple-II - I wonder if this
is the card?
You could use both the TI graphics AND Apple graphics...
Wonder if it used the external video pin for the Apple graphics - had
to, I guess...

Ben