base:memory_management
Differences
This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revision | Next revisionBoth sides next revision | ||
base:memory_management [2022-03-05 11:46] – [Cart pulls only /GAME low (Ultimax mode)] vic-ii memory view white_flame | base:memory_management [2022-03-05 22:51] – typos & minor rewording white_flame | ||
---|---|---|---|
Line 30: | Line 30: | ||
|$37 +55 %111 |BASIC |I/O |KERNAL|Default| | |$37 +55 %111 |BASIC |I/O |KERNAL|Default| | ||
- | WARNING: Don't use INC to go from %111 to %000, as that will turn on the tape write head on the next bit up and do bad/ | + | ***WARNING***: Don't use INC $01 to switch modes from %111 to %000, as that will turn on the tape write head on the next bit up and do bad/ |
+ | |||
====== With Cartridges ====== | ====== With Cartridges ====== | ||
Line 39: | Line 41: | ||
* /IO2 = $DF00 - $DFFF | * /IO2 = $DF00 - $DFFF | ||
- | /ROML and /ROMH are active on reads depending on how the cartridge sets the configuration inputs. | + | /ROML and /ROMH are active on reads depending on how the cartridge sets the configuration inputs. |
Line 59: | Line 61: | ||
===== Cart pulls /EXROM + /GAME low ===== | ===== Cart pulls /EXROM + /GAME low ===== | ||
- | ROML is before BASIC, and is swapped out with the LORAM bit in $01; while ROMH replaces BASIC and is swapped | + | ROML is before BASIC, and is swapped out with the LORAM bit in $01. |
^$01 value ^$8000-9FFF ^$A000-BFFF ^$D000-DFFF ^$E000-FFFF ^Notes^ | ^$01 value ^$8000-9FFF ^$A000-BFFF ^$D000-DFFF ^$E000-FFFF ^Notes^ | ||
Line 79: | Line 81: | ||
|RAM |unmapped |**__ROML__** |unmapped |I/O |**__ROMH__**| | |RAM |unmapped |**__ROML__** |unmapped |I/O |**__ROMH__**| | ||
- | The VIC-II will also see the first 4kB of ROMH at $3000-3FFF in all of its 16kB banks, | + | The VIC-II will also see the first 4kB of ROMH at $3000-3FFF in all of its 16kB banks, |
Line 85: | Line 87: | ||
- | ===== Related: from Graham' | + | ====== Related: from Graham' |
In the C64/C128 series of computers, slightly modified versions of the 6502 were used. The modifications did not affect the functional part of the processor itself. Only a so-called processor port was added. This port, in combination with an external PLA, was used to map ROM and I/O areas into the 64KB RAM of the C64. Also, some bits of the port were used for the legendary Datasette. | In the C64/C128 series of computers, slightly modified versions of the 6502 were used. The modifications did not affect the functional part of the processor itself. Only a so-called processor port was added. This port, in combination with an external PLA, was used to map ROM and I/O areas into the 64KB RAM of the C64. Also, some bits of the port were used for the legendary Datasette. |
base/memory_management.txt · Last modified: 2022-04-17 05:36 by white_flame