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SAM: Difference between revisions
From CoCopedia - The Tandy/Radio Shack Color Computer Wiki
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registers |
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| Line 5: | Line 5: | ||
{| class="wikitable" | {| class="wikitable" | ||
! | ! Address | ||
! Shorthand name | ! Shorthand name | ||
! Function | ! Function | ||
|- | |- | ||
|FFC0 | |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 | |||
|- | |||
|FFC7 | |||
|VOFS1 | |||
|SAM F1 set bit to add $200 to video offset | |||
|- | |- | ||
|FFC8 | |||
| | | | ||
| | | | ||
|- | |||
|FFC9 | |||
|VOFS2 | |||
|SAM F2 set bit to add $400 to video offset | |||
|- | |||
|FFC8 | |||
| | | | ||
| | | | ||
|- | |- | ||
| | |FFCB | ||
| | |VOFS3 | ||
| | |SAM F3 set bit to add $800 to video offset | ||
|} | |} | ||
[[Category:Hardware]] | [[Category:Hardware]] | ||
Revision as of 09:48, 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 |
|---|---|---|
| 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 |
| FFC7 | VOFS1 | SAM F1 set bit to add $200 to video offset |
| FFC8 | ||
| FFC9 | VOFS2 | SAM F2 set bit to add $400 to video offset |
| FFC8 | ||
| FFCB | VOFS3 | SAM F3 set bit to add $800 to video offset |
