Difference between revisions of "Memory Map"
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<table border width=80%> | <table border width=80%> | ||
<tr><th>Memory Range<th>Accessibility<th>Device</th></tr> | <tr><th>Memory Range<th>Accessibility<th>Device</th></tr> | ||
− | <tr><td>$0000-$003F</td><td>RW</td><td>STIC Registers</td></tr> | + | <tr><td>$0000-$003F</td><td>RW, [[VBlank Period 1]]</td><td>STIC Registers</td></tr> |
<tr><td>$0100-$01EF</td><td>RW</td><td>[[Scratchpad RAM]]</td></tr> | <tr><td>$0100-$01EF</td><td>RW</td><td>[[Scratchpad RAM]]</td></tr> | ||
<tr><td>$01F0-$01FF</td><td>RW</td><td>PSG Registers</td></tr> | <tr><td>$01F0-$01FF</td><td>RW</td><td>PSG Registers</td></tr> | ||
<tr><td>$0200-$035F</td><td>RW</td><td>[[System RAM]]</td></tr> | <tr><td>$0200-$035F</td><td>RW</td><td>[[System RAM]]</td></tr> | ||
<tr><td>$1000-$1FFF</td><td>R</td><td>[[Executive ROM]]</td></tr> | <tr><td>$1000-$1FFF</td><td>R</td><td>[[Executive ROM]]</td></tr> | ||
− | <tr><td>$3000-$37FF</td><td>R</td><td>[[Graphics ROM]]</td></tr> | + | <tr><td>$3000-$37FF</td><td>R, [[VBlank Period 2]]</td><td>[[Graphics ROM]]</td></tr> |
− | <tr><td>$3800-$39FF</td><td>RW</td><td>[[Graphics RAM]]</td></tr> | + | <tr><td>$3800-$39FF</td><td>RW, [[VBlank Period 2]]</td><td>[[Graphics RAM]]</td></tr> |
</table> | </table> | ||
Revision as of 23:55, 10 January 2005
Official Memory Map
The "official" memory map published by Mattel is included below.
Memory Range | Accessibility | Device |
---|---|---|
$0000-$003F | RW, VBlank Period 1 | STIC Registers |
$0100-$01EF | RW | Scratchpad RAM |
$01F0-$01FF | RW | PSG Registers |
$0200-$035F | RW | System RAM |
$1000-$1FFF | R | Executive ROM |
$3000-$37FF | R, VBlank Period 2 | Graphics ROM |
$3800-$39FF | RW, VBlank Period 2 | Graphics RAM |
Additional Memory Aliases
Note that the official memory map shown above is actually incomplete, due to the fact that the STIC and the Graphics RAM chip incompletely decoded addresses that were placed on the address bus.
Memory Range | Accessibility | Device |
---|---|---|
$3A00-$3BFF | RW | Graphics RAM |
$3C00-$3DFF | RW | Graphics RAM |
$3E00-$3FFF | RW | Graphics RAM |
$4000-$403F | W | STIC Registers |
$7800-$79FF | W | Graphics RAM |
$7A00-$7BFF | W | Graphics RAM |
$7C00-$7DFF | W | Graphics RAM |
$7E00-$7FFF | W | Graphics RAM |
$8000-$803F | W | STIC Registers |
$B800-$B9FF | W | Graphics RAM |
$BA00-$BBFF | W | Graphics RAM |
$BC00-$BDFF | W | Graphics RAM |
$BE00-$BFFF | W | Graphics RAM |
$C000-$C03F | W | STIC Registers |
$F800-$F9FF | W | Graphics RAM |
$FA00-$FBFF | W | Graphics RAM |
$FC00-$FDFF | W | Graphics RAM |
$FE00-$FFFF | W | Graphics RAM |