Extension Multicoloric?

This is the right place to discuss on how to implement hardware vsync, adding a VIA or AY chipset, puting multiple roms, or how to design a new flash expansion card.
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Extension Multicoloric?

Post by peacer » Sun Sep 09, 2018 4:29 pm

https://www.oric.org/ftp/ceo/ceomag/dow ... -09ocr.pdf

When I was browsing the old magazines on Oric.org, I came across an interesting article in a magazine. In the 1985 issue of Microric magazine, an extension called "Multicoloric" was mentioned. As far as I understand, this device allows 16 of the available 4096 colors to be programmed and used on the HIRES screen at the same time.

I was really surprised. Such a device that was conceived and made for Oric in 1985 could actually make a very important breakthrough for Oric. Perhaps I did not fully understand the project because my French is much worse than my English. Do you have any information about this hardware?

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Re: Extension Multicoloric?

Post by Symoon » Sun Sep 09, 2018 5:04 pm

Hi Peacer,
I think Jede tried to build it, but I seem to recall it had many miskates or lack of details so I'm not sure he managed to make it work.
Jede will tell you better than I do when he comes around.

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Re: Extension Multicoloric?

Post by Dbug » Sun Sep 09, 2018 5:15 pm

The principle is not very complex:
- The ORIC outputs 1 bit RGB colors, which can be counted as a color value index from 0 to 7
- The card intercept this output and use the index to control the Thomson DAC/palette chip to replace the input value by another value using a small array internally.

That's it really :)

What makes the card complex is all the part for programming the videochip (including the additional register to indicate a vertical position where the card will use the second set of 8 colors).

With what the ULA decapping told us and the few experiments we did, it would be kind of cool to redesign a simpler version of this card, and use it with multiple Oric outputs at the same time :)

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