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Re: IIGS ROM chip questions

Dan Foster wrote:

What's the speed? 120ns? 150ns? I know the DRAM was 120ns but less sure
about the ROM.

Would a 27C010 do? (Assuming one had a 32-to-28-pin socket adapter,
especially if on a ROM 01 system.)


150ns is fast enough, the part number on one of the EPROMs in a ROM 3
is M5M27C100K-15. Actually 150ns if fast enough for DRAM too. Quite a
few of the earlier IIgs memory cards from Apple had 150ns RAM soldered
on.


On a different tangent -- this time, RAM-related:

Is banks $80 through $EF (ROM 01) or $80-$DF + $E2-$EF (ROM 03)
controlled by the FPI as fast RAM? Or does memory accesses to these
banks slow down to the slow RAM access?


On both ROM 1 and ROm 3, Banks $E1 and $E0 are the only slow banks which
are controlled by the Mega II. Everything else is controlled by the FPI.

Wayne