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Performa 600 Anyone Added the Cache

trag

Well-known member
I recently received a lot of logic boards and sundry via Ebay, and there are two P600 boards included.   I thought they were IIvx at first, until I discovered that the P600 is just like the IIvx, except for the lack of cache and FPU.

So those solder pads are just sitting there, staring at me.  Almost chanting, "Populate us with SRAM and TAG RAM chips...."

Anyone done it or read about it?

 

68kMacx86

Well-known member
I recently received a lot of logic boards and sundry via Ebay, and there are two P600 boards included.   I thought they were IIvx at first, until I discovered that the P600 is just like the IIvx, except for the lack of cache and FPU.

So those solder pads are just sitting there, staring at me.  Almost chanting, "Populate us with SRAM and TAG RAM chips...."

Anyone done it or read about it?
i wanna add the fpu

 

Fizzbinn

Well-known member
@trag Did you ever try doing this? I'm still working on my battery bombed Iivx board but thinking about plan B, the cache end of my IIvx board is fine and I just bought a cheapish Performa 600...
 

beachycove

Well-known member
Anything that can be done to assist a P600 is perhaps a good thing, but the IIvx is still no speed demon. Just saying…. It’s a shame these machines can’t run System 6, because there they might have done okay.

I say this as someone who, back in the early 90s, bought a P600 new (upgraded in later years to a IIvx), and who used it for years. It was reliable, and I did a lot of good work on it, but all told, it was a really bad decision to buy that P600. Should have read the scathing reviews first, and bought a different machine.
 

mdeverhart

Well-known member
My family’s first Mac was a IIvx - in retrospect, maybe not the best purchase, but it served us well until something (we think a Zip drive) fried the SCSI chip and it would no longer boot. We managed to get Iomega to buy us a refurbished Centris 650 logic board as a replacement, which was much more capable in the long run!
 

Fizzbinn

Well-known member
My interest in these infamous Macs is partially because they seem so unloved! …I get their faults but they still are pretty interesting to me:
  • First use of a metal case design that would be used up until the PM 7100
  • First desktop case to support an internal CD-ROM
  • Unique logic board architecture - the love child of a Mac IIci and LC…
  • The first ”high end” Performa
  • The first Mac with a built in L2 cache
 

trag

Well-known member
@trag Did you ever try doing this? I'm still working on my battery bombed Iivx board but thinking about plan B, the cache end of my IIvx board is fine and I just bought a cheapish Performa 600...

No, I did not. In another thread a kind person provided good photos of the cache area of the IIVX, allowing me to identify the chips. The Tag RAM was available at a (to me) affordable price, but I dithered a little too long and someone bought up all of the Tag RAM chips. Perhaps I should not have drawn attention to them....

Anyway, gave up on that idea for now. There are plenty of other projects to keep me busy. If I try really hard I can stretch the Acard 7722 => 7726 project out into a full year. :)

Actually, I'm waiting on heat sinks now. It seems like everything ships on a slow boat from China these days.

Edit: And moments after writing that complaint, Amazon updated my shipment arrival date from some time in January to this Friday (dec. 3). Are they watching me?
 
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trag

Well-known member
@Bolle Hmmm. What do folks think about substituting the IDT71B74 for the ATT7C174? Datasheets below.

The chips on the IIvx board appear to be -15 speed rating. I have a few IDT71B74S10 on hand. They were kind of expensive. I have my eye on some IDT71B74S12 at $1.60 each.
 

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Bolle

Well-known member
Perhaps I should not have drawn attention to them....
No worries, I had them on my watchlist before you mentioned them back then and it was just the moment I started building the first accelerators that needed them ;)
I actually used them all already and they’re long gone.
Got IDT71B74s now. They’re interchangeable and both types work exactly the same. (at least where I could test them - on the Turbo040, Carrera, PowerCache and DiiMOs)
 

trag

Well-known member
@Bolle I didn't realize you picked them up. That's actually wonderful, because you've been producing great stuff with them.

Good to know about the IDT71B74. Thank you.
 
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