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rf6847 core

Posted: Thu Oct 17, 2024 11:19 am
by Rob Finch
I have been enthused to create a 6847 core in System Verilog. It will be a slight modification due to the intended output to a VGA monitor in 800x600 mode.
The display will be 50 by 25 characters instead of 32x16.
Alpha / graphics modes work in a manner similar to the 6847.
100x100, 200x100, 200x150, 200x300, 400x300 (full graphics mode)
instead of
64x64, 128x64, 128x96, 128x192,256x192

Output is the same 8 colors rendered with 6-bit RGB (2,2,2)
chars are 8x12.
Display RAM (16kB) is embedded in the core, so that external multiplexors are not needed.
There is a built in char ROM.

Meant mainly to be used in a system-on-chip.

Re: rf6847 core

Posted: Thu Oct 17, 2024 11:52 am
by Rob Finch
Added legacy operation mode by pulling the 'leg' signal high.
32x16 chars centered in the display.

Re: rf6847 core

Posted: Sat Oct 19, 2024 1:27 am
by Rob Finch
The photo is crappy. IRL looks much better. Taken with a phone which thought it was a QR-code.
1st mile stone: text output.
At reset a randomizer fills the screen with random characters.
rf6847 txt mode
rf6847 txt mode

Re: rf6847 core

Posted: Sat Oct 19, 2024 1:29 pm
by sark02
Nice work!