Macintosh Iici build questions/MMU

[T-Man]

I have a battery bombed Iici with several legs of the MMU (and multiple traces) eaten away. Aside for the MMU, the other chips look salvageable. I have a Bolle Iici new board and some parts for it and had planned to use a IIsi board to salvage chips /IC's as a backup. However, now looking closer and before starting a lot of work, I'm not so sure about the MMU. The text on the MMU from battery bombed CI is barely visible but is consistent with this picture of a CI MMU I enlarged from "Recap-A-Mac". The IIsi MMU is a picture of the board I actually have. Can I use the MMU from the IIsi board to replace the damaged one on the Iici board?

 

[DevyDevly]

Hi @T-Man.

Late to the party here, but... it would seem so - here's two of my IIci boards with the VGT8002-6216 chip.

Ta,
Devy

 

[Kai Robinson]

Nice to know, it's the part number beginning with 343 that's the apple part number.

 

[T-Man]

So it’s looking like the MMU on IIsi and IIci are the same chip. The build will be a while but will give it a shot. Thank you for posting. Will go look again, on looking at the traces leaving the chip, there seems to be diffeneces.

 

[DevyDevly]

I was re-reading this and might have made a mistake - apologies.
The MDU (UK11) on my IIci machines is either a 343S1059-A, 343S1059-B, or 343S1018-A.
It was the RBV (UE9) that is the 343S1019-A.
i.e. I don't think you replace a IIci MDU (UK11) chip with a 343S1019.

 

[T-Man]

Bummer….not finding the part number on another board to replace UK11 MDU on the IIci board…. maybe file some edges and microsurgery someday

 

[DevyDevly]

Bummer….not finding the part number on another board to replace UK11 MDU on the IIci board…. maybe file some edges and microsurgery someday

I checked the MDU on my IIsi and it’s a 343S1018-A !

 

[T-Man]

Relooking at the boards I have (one battery bombed IIci and three battery bombed IIsi) and online pictures now pretty sure I have a number to add for MDU identified both on IIci and IIsi logic boards. That is 344S1018-03 which is both on the Recap-a-mac picture of IIci logic board and a IIsi board that I have.

Is this part number the only number on the chip that matters, ie marks them as the same? All of the other numbers match EXCEPT the top row.

 

[Kai Robinson]

The only part number that matters is the apple one - 344S1018 - the others are the internal designation for the part, as they were made by Philips, VLSI - whoever had capacity, there were multiple sources.