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Home Forums 68 PIN VRAM Spec — #2 68 PIN VRAM Spec — #2
Post #2 by Trash80toHP_Mini
Source Forum68 PIN VRAM Spec — #2
Category68k
Post DateSat, 27 Jul 2013 - 18:19
Original URLhttps://68kmla.org/bb/threads/68-pin-vram-spec.28533/
Post
It's in the DevNote Block Diagram:

Connection between ASIC MEMCjr & VRAM is VA0-8 = 9 address bits (lines?) = 512k VRAM max as I read it, SIMM select would be the wild card.

Check the DevNotes to see if any other Mac with MEMCjr on board addresses four VRAM SIMMs. That's doubtful, few (any at all?) video subsystems supported 24bit Color at anything over 16" Resolution, which would require 3MB of VRAM. So I doubt MEMCjr would have that capability.

The first Mac to have VRAM SIMMs may have the full spec & pinout, but my guess it's in DC&DftMF.

mp.ls