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LoganDarkyesterday at 8:30 PM1 replyview on HN

The character ROM was not read and processed by the CPU. The CPU set some bytes in video RAM, which served as indexes into the character ROM by the video output hardware.

I believe on some systems there were some tricks that allowed some bitmap display by redefining glyphs. One example off the top of my head is The 8-Bit Guy's Planet X2, which can use text mode but with glyphs redefined to use for icons, units, terrain, UI, etc.


Replies

worthless-trashtoday at 6:22 AM

I believe you are correct, VGA even had character rom, where 'individual pixels' were not drawn by the CPU itself, the software presented an array of indexes into the rom and the vga hardware itself blitted the characters onto the screen.