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Old 25 September 2013, 05:33   #18
RedskullDC
Digital Corruption

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Join Date: Jan 2007
Location: Dorrigo/Australia
Age: 57
Posts: 342
Hi Tony, et al.

Quote:
Originally Posted by Toni Wilen View Post
Technically it is E0 ROM that always appears at 0 (if 1M capable MB, don't remember what 2M capable MBs do but I think it was one of the A8/B0 areas).
Should always be the $E0 bank that appears at $00 when using 1/2MB roms and *OVR is active.
(A19 active for 1MB, A19 and A20 active for 2MB).

Amiga Address Lines:
A A A A A
2 2 2 2 1
3 2 1 0 9

0 0 0 0 0 $0 ROM appears at $00 when *OVR low
1 0 1 0 1 $A8 System ROM selected (2MB area)
1 0 1 1 0 $B0 System ROM selected (2MB area)
1 1 1 0 0 $E0 System ROM(lst half if 1MB ROM)
1 1 1 1 1 $F8 System ROM(2nd half if 1MB ROM)


Cheers,
Red


Last edited by RedskullDC; 25 September 2013 at 05:38.
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