Difference between revisions of "Next Memory Bank Select"
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|Number=$DFFD | |Number=$DFFD | ||
|ShortDesc=Provides additional bank select bits for extended memory. | |ShortDesc=Provides additional bank select bits for extended memory. | ||
| − | |Readable= | + | |Readable=No |
| − | |Writable= | + | |Writable=Yes |
|Subsystem=Memory map | |Subsystem=Memory map | ||
|PortMask=%1101 1111 1111 1101 | |PortMask=%1101 1111 1111 1101 | ||
}} | }} | ||
| + | bits 3:0 = most significant bits of the 16K RAM bank selected in {{PortNo|$7FFD}} | ||
| + | |||
| + | Port 0xDFFD bits 3:0 are combined as the highest bits with the bank selected in port 0x7FFD to form a 7-bit bank number. | ||
Revision as of 10:16, 31 December 2019
| Number | $DFFD |
|---|---|
| Decimal | |
| Short desc. | Provides additional bank select bits for extended memory. |
| Bit Mask | %1101 1111 1111 1101 |
| Readable | No |
| Writable | Yes |
| Subsystem | Memory map |
bits 3:0 = most significant bits of the 16K RAM bank selected in Memory Paging Control ($7FFD / 32765)
Port 0xDFFD bits 3:0 are combined as the highest bits with the bank selected in port 0x7FFD to form a 7-bit bank number.