Power Macintosh 7100/80 Cache

[T-Man]

Is this a picture of the 7100/80 L2 cache? If it is, is it worth replacing for computer function. I have a 7100/80 using the DB15 for video and if this chip is installed the computer will not boot but does boot when I remove it.

 

[Patrick]

Cache chips's are awesome and dramatically speed up the speed of the computer.
...
however, at least for me, i've had a hard time trying to find them.

If you can find a replacement its totally worth it.

 

[Fizzbinn]

Yes, that appears to be a L2 cache module. The connector notches indicate it would FIT in the 6100/7100/8100 PMs, but that connector is also shared with the 62xx series which use combo ROM/L2 cache modules. Maybe it's one of those and not just a dead Cache module?

Can you post a picture of the other side? I'd love to add it to my PPC L2 cache resource article:

https://tinkerdifferent.com/resources/ppc-macintosh-l2-cache-modules.19/

 

[Fizzbinn]

Cache chips's are awesome and dramatically speed up the speed of the computer.
...
however, at least for me, i've had a hard time trying to find them.

If you can find a replacement its totally worth it.

The L2 Cache modules for PM 6100/7100/8100 Macs seem extra rare, I see ones for later Power Macs on eBay from time to time but not these.

A G3/G4 PDS CPU upgrade is a much bigger performance boost but they go for several hundred these days. Would be cool if these got recreated, especially a 512MB or 1024MB version. (FYI the one in this thread shows 256KB of cache on that one side)

 

[T-Man]

Here is the other side. The other chip I guess is the ROM, the machine will boot with the ROM in either slot if the pictured chip is absent.

 

[Fizzbinn]

Here is the other side. The other chip I guess is the ROM, the machine will boot with the ROM in either slot if the pictured chip is absent.

Thanks, no ROM chips there (would be 4 pretty big ones) there so this is not a combo ROM/L2 cache module from a 6200. Those small chips are likely just part of the cache logic. I guess some component(s) just went bad on your L2 cache module :-/

 

[T-Man]

Just checking for grounds on the caps and IC's, the small IC in the center on the backside picture has pins 5 and 7 to ground....cannot find a data sheet on it though....the numbers are AV70-1 then 9508 on the IC itself...?anyone know what specifically I should search for to find a data sheet for the chip?

 

[trag]

Just checking for grounds on the caps and IC's, the small IC in the center on the backside picture has pins 5 and 7 to ground....cannot find a data sheet on it though....the numbers are AV70-1 then 9508 on the IC itself...?anyone know what specifically I should search for to find a data sheet for the chip?

IIRC, AV70-1 is a ICS chip. full part number is AV9170-01CS08. It's a clock delay or clock synchronization chip.

ICS = Integrated Circuit Systems

IIRC, the chip takes a clock input and outputs the same clock, except.... It also takes a second clock input and it aligns the phase of the output of the first signal with the second signal.

 

[T-Man]

Thanks. So it looks like that on chip VDD is shorted to ground. I found another cache and it works fine.

 

[T-Man]

If anyone is interested in a non working 7100 cache with its AV9170 shorted to ground, I’ll send it.