Backup RAM: Difference between revisions
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[[68k memory map|Memory region]]: $D00000~$D0FFFF (Mirrored up to $DFFFFF ?). | [[68k memory map|Memory region]]: $D00000~$D0FFFF (Mirrored up to $DFFFFF ?). | ||
== | == Data structure == | ||
*$D00000~$D0000F: Nothing ($00) | |||
*$D00010: "BACKUP RAM OK !",$80 | |||
*$D00020.l: ? | |||
*$D00021.b: btst 0,1,2,3,4 | |||
*$D00024.l: adresse ? | |||
*$D00034.l: adresse ? | |||
*$D00038.w: ? bit 4 tst | |||
*$D0003A: Start of ? (13 bytes) | |||
*$D00042.b: tst ? | |||
*$D00043.b: tst ? | |||
*$D00044.w: ? | |||
*$D00046.b: SOUND_STOP, No sound at all if non-zero | *$D00046.b: SOUND_STOP, No sound at all if non-zero | ||
*$D00047.b: Number of detected slots | *$D00047.b: Number of detected slots | ||
*$D00048.l: ? | |||
*$D0004C.b: ? ($3B) | |||
*$D00058.b: First valid slot | *$D00058.b: First valid slot | ||
*$D00108.b: Last tested slot | *$D0005E.b: Something to do with tested slot? tst | ||
*$D0005A.b: heure ? | |||
*$D00060.w: tst ? | |||
*$D00104: year,month,day ? (3 bytes) Modify date | |||
*$D00108.b: Last tested slot | |||
*$D00109.b: Compared with 8 | |||
*$D0011A: Start of ? | |||
*$D00122.b: ? ($23) | |||
*$D00124: adresses ? (4 bytes * nb of slots ?) | |||
*$D00144: Date (Year, Month, Day, ? *8 ?) Creation date | |||
*$D001AC.l: $F0F0F0F0 | |||
*$D001B0.w: $FFFF | |||
*$D002A0: Title of game (16 bytes *8 ?) | |||
*$D00320: ? | |||
[[Category:Cartridge systems]] | [[Category:Cartridge systems]] | ||
Revision as of 23:28, 16 September 2011
The backup RAM is a battery-powered 64KiB RAM space used by MVS systems to store game scores, cab infos and income logs. Access is handled by the BIOSes.
Memory region: $D00000~$D0FFFF (Mirrored up to $DFFFFF ?).
Data structure
- $D00000~$D0000F: Nothing ($00)
- $D00010: "BACKUP RAM OK !",$80
- $D00020.l: ?
- $D00021.b: btst 0,1,2,3,4
- $D00024.l: adresse ?
- $D00034.l: adresse ?
- $D00038.w: ? bit 4 tst
- $D0003A: Start of ? (13 bytes)
- $D00042.b: tst ?
- $D00043.b: tst ?
- $D00044.w: ?
- $D00046.b: SOUND_STOP, No sound at all if non-zero
- $D00047.b: Number of detected slots
- $D00048.l: ?
- $D0004C.b: ? ($3B)
- $D00058.b: First valid slot
- $D0005E.b: Something to do with tested slot? tst
- $D0005A.b: heure ?
- $D00060.w: tst ?
- $D00104: year,month,day ? (3 bytes) Modify date
- $D00108.b: Last tested slot
- $D00109.b: Compared with 8
- $D0011A: Start of ?
- $D00122.b: ? ($23)
- $D00124: adresses ? (4 bytes * nb of slots ?)
- $D00144: Date (Year, Month, Day, ? *8 ?) Creation date
- $D001AC.l: $F0F0F0F0
- $D001B0.w: $FFFF
- $D002A0: Title of game (16 bytes *8 ?)
- $D00320: ?