Plus 3 Memory Paging Control
From SpecNext official Wiki
Revision as of 15:41, 18 August 2017 by wiki>Hyphz (Created page with "{{Port |Number=$1FFD |ShortDesc=Controls ROM paging and special paging options from the +2a/+3. |Readable=No |Writable=Yes |Subsystem=Memory Map }} Bit mapped to control pagin...")
| Number | $1FFD |
|---|---|
| Decimal | |
| Short desc. | Controls ROM paging and special paging options from the +2a/+3. |
| Bit Mask | |
| Readable | No |
| Writable | Yes |
| Subsystem | Memory Map |
Bit mapped to control paging options.
| Bit | Effect |
|---|---|
| 5-7 | Undocumented |
| 4 | Printer Port Strobe |
| 3 | Disk motor enable |
| 2 | Normal mode: High bit of ROM selection.
Special mode: High bit of memory configuration number. |
| 1 | Special mode: Low bit of memory configuration number. |
| 0 | Paging mode. 0=Normal, 1=Special. |