3 ms·
EGA cards were truly funky beasts. There was a "64 color" stunt where you could switch the 16 color palette fast enough to have up to 4 different palettes visib
by h2odragon 5y ago
EGA cards were truly funky beasts. There was a "64 color" stunt where you could switch the 16 color palette fast enough to have up to 4 different palettes visible on screen at once.
There were fringe flavors of compatibles, with extra capabilites. 400 scanline modes that enabled 43 and 50 lines text modes hover in my memory.
- bitwize 5y agoPfff... getting more colors on screen than you have palette entries is not a stunt at all... not on a thoughtfully designed system with raster interrupts. On the Amiga you could even program the copper to do this work for you, freeing up the CPU for other tasks.
- shdon 5y ago400 scanline modes gave us 50 lines of text by virtue of loading the 8x8 pixel font (400/8=50). There was no incompatible trickery going on for 43 line mode. That was just the 8x8 pixel font at the standard 350 scanlines (350/8=43.75). The palette was weird because changing palette entries away from the standard 16 CGA colours was impossible in 200 scanline modes. It was only possible in 350 scanline mode (and also on VGA, but I digress). That's because the EGA could connect (and often would be connected) to CGA monitors and adjusted the pinout of the connector accordingly. This meant just 1 bit per colour channel and 1 intensity bit. The full EGA palette required 2 bits per colour channel and could only be used on actual EGA monitors. The way IBM ensured that was limiting palette changes to the 640x350 mode.
- TonyTrapp 5y agoHow about 1024 colors on CGA? https://int10h.org/blog/2015/04/cga-in-1024-colors-new-mode-illustrated/ https://int10h.org/blog/2015/04/cga-in-1024-colors-new-mode-...