ROMBIOS programming sequence (other registers left on hardwired boot-time defaults):
| Register \ Mode | 720x400 | 640x480 | 320x400 | XXXx400 | XXXx480 |
|---|---|---|---|---|---|
| AA | CC | A4 | AA | B7+fuzzAA | 00+fuzzAA |
| AB | 02 | 02 | 02 | 02 | 03 |
| BF | 0A | 0A | 0A | 0A | 0A |
| 80 | 0C | 0A | 0A | 0C | 0B |
| 81 | 67 | 2F | 53 | 67 | 3F |
| 82 | BF | B3 | BF | BF | B3 |
| 8D | 08 | 00 | 00 | 00 | 00 |
| 90 | 7F | 7F | 7F | 7F | 7F |
| 91 | FF | 00 | FF | FF | 00 |
| 92 | 7F | 70 | 7F | 7F | 70 |
| 94 | B3 | B3 | B3 | B3 | B3 |
| 96 | 58 | 31 | 31 | 58 | E7 |
| 97 | 03 | 03 | 03 | 03 | 03 |
| 98 | Skipped | DF | 00 | DF | 70 |
| 99 | Skipped | 03 | 02 | 03 | 01 |
| 9A | 1B | 20 | 1A | 25 | 26 |
| 9B | 00 | 00 | 00 | 00 | 00 |
| 9C | 04 | 04 | 04 | 04 | 04 |
| 9D | 00 | 00 | 00 | 00 | 00 |
| 9E | DE | B6 | BA | A9 | AB |
| 9F | 02 | 02 | 02 | 02 | 02 |
| A0 | 58 | 31 | 31 | 58 | E7 |
| A1 | 03 | 03 | 03 | 03 | 03 |
| A2 | 6A | 68 | 66 | 74 | 70 |
| A3 | 00 | 00 | 00 | 00 | 00 |
| A4 | 4E | 4B | 4E | 4E | 4B |
| A5 | 00 | 00 | 00 | 00 | 00 |
| A6 | 0B | 0B | 0C | 0B | 0B |
| A7 | 00 | 00 | 00 | 00 | 00 |
| A8 | 0C | 57 | 0C | 0C | 57 |
| A9 | 02 | 02 | 02 | 02 | 02 |
| AC | 23 | 23 | 22 | 24 | 23 |
| AD | 00 | 00 | 00 | 00 | 00 |
| AE | 29 | 23 | 2A | 2A | 20 |
| AF | 00 | 00 | 00 | 00 | 00 |
| B9 | 30 | 30 | 30 | 30 | 30 |
| BE | 60 | 66 | 60 | 5B | 62 |
| C2 | 2B | 2C | 2A | 32 | 32 |
ROMBIOS Post-programming sequence
| Register | Value |
|---|---|
| B0 | 00 |
| B3 | 00 |
| 0A | 7E |
| 0B | 40 |
| 0E | 3F |
| 0F | 03 |
| 1E | 8B |
| 1F | 02 |
| 20 | 96 |
| 22 | 96 |
| 29 | 10 |
| 2C | 24 |
| 31 | B2 |
| 32 | 04 |
| 33 | 14 |
| 35 | 0F |
| 3C | 3C |
| 3D | 00 |
| 19 | 00 |
| 8C | 20 |
| B3 | 01 |
| B3 | 00 |
| 3E | 00 |
| BF | 02 |
| 95 | 20 |
FuzzAA
| Depth | FuzzAA |
|---|---|
| <= 8 | 0 |
| <= 16 | 10 |
| Other | 15 |
These values are derived from page 5-11 of G400 manual
| Depth | Delay |
|---|---|
| 8 | 31 |
| 15 | 21 |
| 16 | 21 |
| 24 | 17 |
| 32 | 16 |
With equation ”FuzzAA = 31 – delay”