The integrated palette contains 256 color entries. VGA ports and native I/O aliases address the same programming interface.
| Operation | VGA port | Native I/O |
|---|---|---|
| Write index | 0x3C8 | +0xB0 |
| Data | 0x3C9 | +0xB1 |
| Pixel mask | 0x3C6 | +0xB2 |
| Read index | Write 0x3C7 | +0xB3 |
| DACState | Read 0x3C7 | — |
Byte data accesses sequence through red, green and blue. A palette word write supplies red in bits 23:16, green in 15:8 and blue in 7:0, then increments to the next color triple. This permits 256 word writes for a full palette. Reads still use bytes.
Command0 selects six- or eight-bit palette output and power-down. Command1 selects 8/16/32-bit pixel mode and palette bypass. Command2 selects cursor mode and contiguous or sparse palette indexing. Cursor colors have their own read/write index and data ports.
The catalogue's palette entry diagrams describe these RGB component programming values. They do not establish the physical width of the internal palette RAM.
At I/O +0xBA, Table 7a describes Command4/signature analysis, while Table 7b describes Palette Status with different fields. The detailed Status table is used for the diagram; the conflicting description remains visible in PALETTE_BA.
All 256 palette entries · RGB word-write format · Cursor
Sources: Technical Spec, p.51, Technical Spec, p.52