Compatibility of the IIci PDS slot with the IIvi/IIvx

[MrFahrenheit]

I’ve long been confused about the IIci PDS slot and what exactly it is compatible with. Apple had a 32kb cache card that was for that slot.

The IIvi/IIvx/Performa 600 all shared the same logic board design and also have a PDS slot. I haven’t tried it, but some have said the IIci cache card works in the IIvi/IIvx.

Can anyone confirm this? If so, is the opposite true (can a card designed for the IIvi/IIvx PDS slot work in the IIci)?

The reason I ask is because Daystar made a 601 card for the IIvi/IIvx PDS slot and does not mention the IIci on the list of compatible machines, which seems odd to me.

 

[Melkhior]

Interesting question.

Apple never talks about the IIci slot as a 'PDS slot' - it's a 'cache card connector' ; DCDMF3 goes out of its way to explain that only cache cards are supported. The IIfx, SE/30 and IIsi have a 'processor-direct slot' (a.k.a. PDS) in that document.

My first reaction would have been that the IIvi family would have had a PDS (being introduced long after the IIsi, SE/30 and IIfx), but actually the repair manual doesn't contain 'pds' or 'direct'; the slot is referred to as an 'accelerator slot', without much details.

Unfortunately I can't find a technical document for the family. It's likely included in "Macintosh Developer Note Number 1, APDA catalog number R0451LL/A", which I can't find online. The LC520 developer's note has this to say on the subject:

Macintosh Developer Note Number 1 also covers the Macintosh IIvx,
the Macintosh PowerBook 145, 160, and 180, and the Macintosh
Quadra 950.

lowendmac's page for the IIvi links a number of accelerators that claim a similar level of compatibility for the IIci, IIvi, IIvx and Performa 600, making it plausible that there is a level of electrical and logical compatibility between them. The IIci slot as described in DCDMF3 has some signals that are explicitly unsupported:

Diagnostic signals (/ROMOE, /DSACK0-/DSACK1, /IPL0-/IPL2, /BR, and CPUDIS) are
needed for Apple's internal use in debugging and for emulator support. They are
documented so that third-party developers can easily make use of emulators or other
hardware debugging tools. The diagnostic signals are not required for cache memory
operations and may not be supported in future implementations of the cache connector.

So it's possible some of those changed between the IIci and the IIvi family...

However without a detailed pinouts of the newer machines' slot, it's hard to say for sure.

 

[beachycove]

I had a P600 from new in the early 90s and recall that PDS cards were not routinely compatible between it and the IIci. I believe that some were, however, so a case by case approach is needed to avoid frying card or logic board or both. I do recall the latter warning clearly, which would imply some electrical incompatibility in the PDS design.

I’m pretty sure that Daystar had a PDS 040 card that worked across the machines in question, however, so if i am right, they must have found a way to engineer around the problem. The same could well apply to the 601 card.

I have not used my P600 in such a long while that I forget the details about the above precisely, but I vividly remember calling up Apple at one stage probably around 1994 in an effort to find some way of speeding the darned thing up. One of my questions concerned a particular 040 card that I was drooling over in MacUser or the like. A new machine was what was recommended…. That was probably good advice, but it had to wait a few years, as my piggy bank was empty, and I never laid my hands on one of the 040 PDS cards first nor last.

 

[MrFahrenheit]

Thanks for the first-hand accounts and the detailed reference.

I found that Daystar sold a different card SKU for the IIci. I’ve never heard of or seen a PowerPC upgrade card for 68030 Macs, so I was intrigued enough to make an offer on the card I found on eBay and bought it.

DayStar Turbo 601 68030 Macintosh PowerPC 100MHz Card | eBay

<p dir="ltr" style="margin-top:0; margin-bottom:0;">DayStar Turbo 601 68030 Macintosh 100MHz Card. I don't believe it has ever been opened, and I don't have the equipment to test it. I can't see why it wouldn't work, but it's ancient so please be aware that repairs may be necessary.</p>

www.ebay.com

I do have a IIvi and IIvx and P600 so I’d be curious to know the benchmark differences between those three models. I would have loved to put one in my IIci to see how that works but I don’t want to blow it up. If Daystar shipped a different card specifically for the IIci then the one for the IIvi definitely won’t work.

It would be interesting if this card could get adapted to work inside an SE/30…

@Bolle do you have an adapter for the SE/30 that works with this Daystar 601 PPC card for the IIvi/IIvx?

 

[volvo242gt]

^I'd expect the P600 and IIvx to perform similarly with it. If I remember correctly, the 600's board is missing the L2 cache, but otherwise is the same as a regular IIvx board, whereas the IIvi's board has the IIcx's processor chip.

A few years ago, I had a IIci compatible Turbo 601 in one of the machines I owned at the time. Gave it to a buddy of mine who's now inactive on the forums.

 

[beachycove]

This publication is the best I’ve found as a reference work for cards/ upgrade options for machines from the II and Quadra era. I’m pretty sure compatibility details will be in there.

https://vintageapple.org/macbooks/pdf/Upgrading_and_Repairing_Macs_Que_1994.pdf

 

[MrFahrenheit]

This publication is the best I’ve found as a reference work for cards/ upgrade options for machines from the II and Quadra era. I’m pretty sure compatibility details will be in there.

https://vintageapple.org/macbooks/pdf/Upgrading_and_Repairing_Macs_Que_1994.pdf

WOW!!!! That is an incredible resource! Thank you so much for sharing!!!

 

[olePigeon]

I used to own the PowerPro for IIci. I used it briefly, then traded it for a Turbo 040. What it offers is to turn your IIci into the slowest PowerPC machine ever made, with 68k emulation even slower than the IIci's original 030.

 

[Fizzbinn]

I used to own the PowerPro for IIci. I used it briefly, then traded it for a Turbo 040. What it offers is to turn your IIci into the slowest PowerPC machine ever made, with 68k emulation even slower than the IIci's original 030.

I hear you, but for some reason I can't explain this fascinates me. ...could you get this type of PowerPro to work in a Mac II with the right Daystar adapter?

 

[MrFahrenheit]

I used to own the PowerPro for IIci. I used it briefly, then traded it for a Turbo 040. What it offers is to turn your IIci into the slowest PowerPC machine ever made, with 68k emulation even slower than the IIci's original 030.

That sounds like a fun experiment!

 

[MrFahrenheit]

I hear you, but for some reason I can't explain this fascinates me. ...could you get this type of PowerPro to work in a Mac II with the right Daystar adapter?

I like the cut of your jib.

 

[volvo242gt]

It may work, using the correct adapter. It's not a PowerPro card, btw. Those were the cards sold for machines like the Centris 650, Quadra 950, etc. The '030 to 601 cards were the Turbo 601.

 

[Bolle]

could you get this type of PowerPro to work in a Mac II with the right Daystar adapter?

No. The Turbo601 only works in RBV-based machines. It’s not compatible with the older GLUE based architecture.

All CPU accelerators made for the IIci are interchangeable with the IIvi/IIvx/P600. The slot is electrically the same except for the cache control signals which are missing on machines that already have cache on the logicboard.
I have a Turbo601 that has the IIvi SKU and it works just fine in my IIci, IIsi (with adapter) and P600.

@Bolle do you have an adapter for the SE/30 that works with this Daystar 601 PPC card for the IIvi/IIvx?

No. SE/30 is GLUE based, so no Turbo601 joy there.

 

[MrFahrenheit]

No. The Turbo601 only works in RBV-based machines. It’s not compatible with the older GLUE based architecture.

All CPU accelerators made for the IIci are interchangeable with the IIvi/IIvx/P600. The slot is electrically the same except for the cache control signals which are missing on machines that already have cache on the logicboard.
I have a Turbo601 that has the IIvi SKU and it works just fine in my IIci, IIsi (with adapter) and P600.


No. SE/30 is GLUE based, so no Turbo601 joy there.

Thanks for the reply, @Bolle !

It’s strange that Daystar sold the Turbo 601 as a different box and SKU for the IIci vs the IIvi/IIvx. Can you post a photo of your Turbo 601 that works in the IIci so I can compare with mine? Perhaps they had different hardware revisions on that card? I just don’t want to fry my card or a computer trying things out.

Based on your reply, the Turbo 601 could never work inside the SE/30? Even if something like this is used?

Stratos Twinspark IIci Cache Slot Accelerator Adapter for Macintosh SE/30 | eBay

Up for sale is a Stratos Twinspark adapter for Macintosh SE/30. This adapter provides your SE/30 with a IIci cache slot and SE/30 PDS passthrough, allowing you to further expand your macintosh system.

www.ebay.com

I’m still very uneducated on all of these slots, accelerators, and machine compatibilities.

 

[olePigeon]

I hear you, but for some reason I can't explain this fascinates me. ...could you get this type of PowerPro to work in a Mac II with the right Daystar adapter?

Edit: Just read Bolle's reply. Would have been funny if it worked.

I never had another computer with a different adapter. I would assume you could do it. Would be funny to see an original LC with the elusive LC adapter & PowerPro.

Now that would probably be the slowest PowerPC ever. Only 10MBs of RAM? Sounds like a fun challenge.

 

[Fizzbinn]

Edit: Just read Bolle's reply. Would have been funny if it worked.

I never had another computer with a different adapter. I would assume you could do it. Would be funny to see an original LC with the elusive LC adapter & PowerPro.

Now that would probably be the slowest PowerPC ever. Only 10MBs of RAM? Sounds like a fun challenge.

…what is the Mac with the biggest swing in performance via commercially available upgrade?

PM 7500? 100Mhz PPC 601 to 1Ghz? PPC 604ev?

 

[joshc]

…what is the Mac with the biggest swing in performance via commercially available upgrade?

Perhaps 60mhz 601 Power Mac 6100 to (not sure what speed) G4 using Sonnet's NuBus G4 accelerator?

 

[MrFahrenheit]

Perhaps 60mhz 601 Power Mac 6100 to (not sure what speed) G4 using Sonnet's NuBus G4 accelerator?

I remember on my 7600, the bus speed was a big limitation to any improvement a card was likely to bring. I had an XLR8 carrier ziff with a G3/300 and it performed well, until I tried to run OS X on it. The slow bus resulted in boot times measured in quarter hours.

How does the bus speed on the 6100 compare?

I do have a G3 upgrade card that came inside a 6100, somewhere, but I’ve never tested its speed.

 

[KnobsNSwitches]

Thanks for the first-hand accounts and the detailed reference.

I found that Daystar sold a different card SKU for the IIci. I’ve never heard of or seen a PowerPC upgrade card for 68030 Macs, so I was intrigued enough to make an offer on the card I found on eBay and bought it.

DayStar Turbo 601 68030 Macintosh PowerPC 100MHz Card | eBay

<p dir="ltr" style="margin-top:0; margin-bottom:0;">DayStar Turbo 601 68030 Macintosh 100MHz Card. I don't believe it has ever been opened, and I don't have the equipment to test it. I can't see why it wouldn't work, but it's ancient so please be aware that repairs may be necessary.</p>

www.ebay.com

I had no idea this existed. What's the performance like?

 

[MrFahrenheit]

I had no idea this existed. What's the performance like?

I don’t know yet. It’s on the way to me right now. I’ll definitely post benchmarks.