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by Olivier26 3433 days ago
> TI with the Speech Synthesizer and the 32K RAM expansion is vanilla to me

Agree

> graphics chip with some significant new features on it, I'd agree that wouldn't count.

Agree too. If the graphics chip was so powerful, it's hard to understand why it was so underused, and not integrated in other microcomputers of this time. The video memory of the TI was 16KB, I had several computers with this size, and you couldn't render with this quality, even statically because at 256*192 it's less than 2,6 bits per pixel. And the number of sprites is more than impressive.
2 comments
nsxwolf 3433 days ago
Actually the TMS9918 is used in a lot of places - in addition to the MSX (which I see you noted below) it was also used in the Colecovision game console and Sega's SG-1000 among others.

The sprite support was great, especially for the late 1970s. Though, I continue to be impressed with what an unencumbered architectire like the Apple II can do with sprites purely in software.

Sega actually kept going with the architecture - the Sega Master System used an upgraded 9918 based chip, and the Genesis/Mega Drive built further on top of that.

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joakleaf 3433 days ago
From Wikipedia: --- • Multicolor mode: 64×48 pixels (each pixel may be any color, all 32 sprites are available)

• Bitmap mode: 256×192 pixels (no more than two colors in an eight pixel row, full 15 color palette + transparent, all 32 sprites available)

• Graphics mode: 32×24 characters (256 8×8 user-definable characters, full 15 color palette + transparent and 32 sprites. ---

The last was the mode accessible from Basic and Extended Basic. I remember longing for the bitmap and multicolor mode.

For the 256x182 mode, the pixel bitmap is 5824 bytes bitmap, plus 1 byte for color info of each 8-pixel (4-bit foreground/4-bit background) which is also 5824 bytes. Total 11648 bytes. Just 2 bits per pixel BTW.

The TI994a had 32 sprites (all single colored 8x8 pixels). You could also magnify them.

Also from Wikipedia: --- The TMS9918 was the basis for the VDP chips in the Sega Master System, Game Gear and Mega Drive. They used additional display modes and registers, and added hardware scrolling capabilities and other advanced features. (Note that the Mega Drive VDP cannot access any of the TMS9918 display modes discussed below.) ---

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