Alternate ROM
From SpecNext official Wiki
| Number | $8C |
|---|---|
| Readable | Yes |
| Writable | Yes |
| Short Description | Enable alternate ROM or lock 48k ROM |
| Bit | Description |
|---|---|
| Values affecting machine immediately | |
| 7 | 1 to enable alternate ROM |
| 6 | 1 to make alternate ROM visible only during writes, 0 to make alternate ROM visible during reads |
| 4 | 1 to lock 48k ROM |
| After soft reset (will be copied to bits 7-4) | |
| 3 | 1 to enable alternate ROM |
| 2 | 1 to make alternate ROM visible only during writes, 0 to make alternate ROM visible during reads |
| 0 | 1 to lock 48k ROM |
Set to 0 upon hard reset.
(new register since core 3.0.5)
(note: Next registers with number higher than $7F are inaccessible from Copper code)