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Apple II graphics chip?

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Does the chip even have a name? Anyone have a pinout and detailed memory map? Thanks.

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The Apple II doesn't have a graphics chip. It has a circuit made from discrete 74LS logic that scans the memory and tickles the composite video signal.

 

I suggest reading:

ftp://ftp.apple.asimov.com/pub/apple_II/documentation/hardware/machines/understanding%20the%20apple%20ii.pdf

..if you want a thoroughly detailed explanation of how the hardware works, down to the component & signal level.

 

A memory map:

ftp://ftp.apple.asimov.com/pub/apple_II/documentation/

ftp://ftp.apple.asimov.com/pub/apple_II/documentation/hardware/machines/Inside%20the%20Apple%20IIe.pdf

ftp://ftp.apple.asimov.com/pub/apple_II/documentation/hardware/machines/Apple%20IIe%20Reference%20Manual.pdf

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I wish that Apple II family would have the similar graphics chips like GITA on Atari 8 bits version or SID on Commodore 8 bits version ! But Steve Jobs or Steve Wozniak does not want to installed them ? Maybe due too costly to make graphics chip on Apple II ?? To shave the extra nicely profit for those co-founder of Apple II without any graphics chip on Apple II systems.

Edited by Caterpiggle

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At the time the Apple II was designed in 1976/1977 low-cost graphics chips didn't exist. SID wouldn't come till 1981, and CTIA/GTIA 1979/1980.

 

I think retrofitting custom graphics to a II+ or IIe would have caused too many compatibility issues. And it most certainly would have taken away a lot of the bare metal feel of the machine that made it so popular and versatile.

 

They would have distracted programmers too much and the system would turn into a videogame console.

Edited by Keatah
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I don't think the cards had anything to do with it. They actually made a couple of cards with the TI graphics chip. The Arcade Board and the Sprite Board. They never became popular.

 

They even made a Super VGA card, too, and that was a flop also. And there was the Video Overlay card, I bet that could have been programmed to do nifty stuff, but this one was late in the game and no one was interested in it.

 

It's just something you don't do on Apple II systems.

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Correct, there were no general purpose "graphics chips" in 1977 and Apple would not have had the skill or money to design a chip or have it manufactured. The text technology is based on the ideas from the TV typewriter (clever shift registers and a character ROM) and the color technology is basically a version of the idea used on the "Dazzle" cards (artifact color) that were in the S-100 computers at the time, and is all based on off-the-shelf chips from the time period.

 

It was not expanded until the Apple IIgs. I guess you could say the Apple IIe had a "graphics chip" as I think the Apple II graphics system was put into the IOU chip.

Edited by R.Cade
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Just correcting , SID is a Sound chip, not a graphics Chip... The Graphics chip of C64 was the VIC-II...

 

Quite well aware of that. It was common that if a computer had a custom graphics chip it also had a custom sound chip.

 

The apple had neither for the reasons stated above. And I'm pretty sure it was the last hobbyist computer built from discrete 74series. If not quite that, it was MOST CERTAINLY the longest running line that had discrete logic.

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Quite well aware of that. It was common that if a computer had a custom graphics chip it also had a custom sound chip.

 

The apple had neither for the reasons stated above. And I'm pretty sure it was the last hobbyist computer built from discrete 74series. If not quite that, it was MOST CERTAINLY the longest running line that had discrete logic.

There were others after the Apple II, just none of the big sellers.

I believe the Exidy Sorcerer is one.

Edited by JamesD

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