MediaWiki:Sitenotice:
2025-12-29: I have restored the wiki to a backup from the end of November. Starting in September 2025, accesses went form the 800MB-1.2GB range per month to 26GB in September, 42GB in October, and 70GB in November with most accesses originating from China. As soon as I realized what was causing all the access problems in November, I shut it down (it had reached 36GB by then) behind a password/login screen. The database had gotten corrupted, and I tried a restore from just before the spike in access but that didn't work. Thus, end of November. I still have the other daily backups so if there were any important additions in December, let me know and maybe they can be recovered. - Allen H.
SAM: Difference between revisions
| Line 8: | Line 8: | ||
! Shorthand name | ! Shorthand name | ||
! Function | ! Function | ||
! Effect | |||
|- | |- | ||
|FFC0 | |FFC0 | ||
|V2CLR | |V2CLR | ||
|SAM V2 bit clear | |SAM V2 bit clear | ||
| | |||
|- | |- | ||
|FFC1 | |FFC1 | ||
|V2SET | |V2SET | ||
|SAM V2 bit set | |SAM V2 bit set | ||
| | |||
|- | |- | ||
|FFC2 | |FFC2 | ||
|V1CLR | |V1CLR | ||
|SAM V1 bit clear | |SAM V1 bit clear | ||
| | |||
|- | |- | ||
|FFC3 | |FFC3 | ||
|V1SET | |V1SET | ||
|SAM V1 bit set | |SAM V1 bit set | ||
| | |||
|- | |- | ||
|FFC4 | |FFC4 | ||
|V0CLR | |V0CLR | ||
|SAM V0 bit clear | |SAM V0 bit clear | ||
| | |||
|- | |- | ||
|FFC5 | |FFC5 | ||
| Line 35: | Line 41: | ||
|FFC6 | |FFC6 | ||
|F0CLR | |F0CLR | ||
|SAM F0 bit clear | |SAM F0 bit clear | ||
| | |||
|- | |- | ||
|FFC7 | |FFC7 | ||
|F0SET | |F0SET | ||
|SAM F0 set bit | |SAM F0 set bit | ||
|add $200 to video offset | |||
|- | |- | ||
|FFC8 | |FFC8 | ||
| Line 47: | Line 55: | ||
|FFC9 | |FFC9 | ||
|F1SET | |F1SET | ||
|SAM F1 set bit | |SAM F1 set bit | ||
|add $400 to video offset | |||
|- | |- | ||
|FFCA | |FFCA | ||
| Line 55: | Line 64: | ||
|FFCB | |FFCB | ||
|F2SET | |F2SET | ||
|SAM F2 set bit | |SAM F2 set bit | ||
|add $800 to video offset | |||
|- | |- | ||
|FFCC | |FFCC | ||
| | |||
| | | | ||
| | | | ||
| Line 64: | Line 75: | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFCE | |FFCE | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFCF | |FFCF | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFD0 | |FFD0 | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFD1 | |FFD1 | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFD2 | |FFD2 | ||
| Line 92: | Line 108: | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFD5 | |FFD5 | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFD6 | |FFD6 | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFD7 | |FFD7 | ||
| Line 108: | Line 127: | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFD9 | |FFD9 | ||
| Line 120: | Line 140: | ||
| | | | ||
| | | | ||
| | |||
|- | |- | ||
|FFDC | |FFDC | ||
| Line 132: | Line 153: | ||
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| | | | ||
| | |||
|- | |- | ||
|FFDF | |FFDF | ||
| | | | ||
| | | | ||
| | |||
|} | |} | ||
Revision as of 22:23, 4 May 2013
The SAM or Synchronous Address Multiplexer is a chip that controls access to RAM memory by the 6809 CPU and the VDG (Video Display Generator).
SAM Registers
| Address | Shorthand name | Function | Effect |
|---|---|---|---|
| FFC0 | V2CLR | SAM V2 bit clear | |
| FFC1 | V2SET | SAM V2 bit set | |
| FFC2 | V1CLR | SAM V1 bit clear | |
| FFC3 | V1SET | SAM V1 bit set | |
| FFC4 | V0CLR | SAM V0 bit clear | |
| FFC5 | V0SET | SAM V0 bit set | |
| FFC6 | F0CLR | SAM F0 bit clear | |
| FFC7 | F0SET | SAM F0 set bit | add $200 to video offset |
| FFC8 | |||
| FFC9 | F1SET | SAM F1 set bit | add $400 to video offset |
| FFCA | SAM F2 bit clear | ||
| FFCB | F2SET | SAM F2 set bit | add $800 to video offset |
| FFCC | |||
| FFCD | |||
| FFCE | |||
| FFCF | |||
| FFD0 | |||
| FFD1 | |||
| FFD2 | |||
| FFD3 | |||
| FFD4 | |||
| FFD5 | |||
| FFD6 | |||
| FFD7 | |||
| FFD8 | |||
| FFD9 | |||
| FFDA | |||
| FFDB | |||
| FFDC | |||
| FFDD | |||
| FFDE | |||
| FFDF |