This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision | ||
mg_notes:apple_iic:accelerator [2017/07/18 02:14] M.G. [MIG RAM Use] |
mg_notes:apple_iic:accelerator [2017/07/25 16:16] (current) M.G. [MIG RAM Use] |
||
---|---|---|---|
Line 9: | Line 9: | ||
==== MIG RAM Use ==== | ==== MIG RAM Use ==== | ||
- | The stock firmware uses MIG RAM page 2 as follows: | + | The stock firmware uses [[mg_notes:apple_iic:mig_chip|MIG]] RAM page 2 as follows: |
* $00 - powerup byte 1 - $33 after init. | * $00 - powerup byte 1 - $33 after init. | ||
Line 15: | Line 15: | ||
* $02,$03 - current accelerator control word. | * $02,$03 - current accelerator control word. | ||
* $04 - keyboard keypress at RESET time, used to detect <key>ESC</key> during reset. | * $04 - keyboard keypress at RESET time, used to detect <key>ESC</key> during reset. | ||
- | * $05-$08 - copies of what should be in Zip Chip $C05c-$c05f registers (respectively). | + | * $05-$08 - copies of what should be in Zip Chip $c05c-$c05f registers (respectively). |
* $10-$17 - used to save zero page locations $00-$07. | * $10-$17 - used to save zero page locations $00-$07. | ||
* Others - apparently unused. | * Others - apparently unused. |