Internal Port Decoding b0-7 Register
From SpecNext official Wiki
| Number | $82 |
|---|---|
| Readable | Yes |
| Writable | Yes |
| Short Description | Enabling internal ports decoding |
| Bit | Description |
|---|---|
| 7 | Enabling Kempston Joystick 2, Joystick I/O ($xx37 / 55) (also MD2 controller) |
| 6 | Enabling Kempston Joystick ($xx1F / 31) (also MD1 controller) |
| 5 | Enabling Datagear DMA Port ($xx6B / 107) |
| 4 | Enabling +3 floating bus |
| 3 | Enabling Plus 3 Memory Paging Control ($1FFD / 8189) |
| 2 | Enabling Next Memory Bank Select ($DFFD / 57341) |
| 1 | Enabling Memory Paging Control ($7FFD / 32765) |
| 0 | Enabling Timex Sinclair Video Mode Control ($xxFF / 255) |
All bits are set to 1 upon soft reset.
(note: Next registers with number higher than $7F are inaccessible from Copper code)