Post #2060964
2026-04-01 04:53 UTC
@Hearth @foone
- Mode 5 is an undocumented mode that disables the color burst while also combining the two mode 4 palettes (cyan/red/white, instead of green/red/yellow or cyan/magenta/white). It also respects the palette intensity bit, so two palettes total.
- Graphics in mode 4 get their color because the two per-pixel bits and the two palette select bits each correspond to one of the RGBI bits for that pixel. So they aren't "palettes" in the traditional sense.
Replies (1)
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@curtmack@floss.social 2026-04-01 05:04
@Hearth @foone - There's a special circuit on IBM CGA cards so they render low-intensity yellow as brown. Some clones lacked this circuit, so they would display a darker yellow instead. Also, since RGBI was a digital signal, RGBI monitors needed their own brown circuit.