Plus 3 Memory Paging Control
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Revision as of 15:24, 28 August 2017 by wiki>Hyphz
Number | $1FFD |
---|---|
Decimal | |
Short desc. | Controls ROM paging and special paging options from the +2a/+3. |
Bit Mask | %0001----------0c |
Readable | No |
Writable | Yes |
Subsystem | Memory map |
Bit mapped to control paging options.
Bit | Effect |
---|---|
5-7 | Undocumented, may be used for extra bits of slot 4 bank select (see Memory Paging Control ($7FFD / 32765)) |
4 | Printer Port Strobe |
3 | Disk motor enable |
2 | Normal mode: High bit of ROM selection.
Special mode: High bit of memory configuration number (see Memory map). |
1 | Special mode: Low bit of memory configuration number. |
0 | Paging mode. 0=Normal, 1=Special. |
Any values written to this port should also be stored in $5B67 if you intend to use any OS routines.