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TwinSpark Powercache incompatible?

ktkm

6502
Hello!

Just bought a ”TwinSpark” cache Adapter from Stratos Technology, to my Daystar Universal Powercache 33 MHz (MC68030FE33B), for use in an SE/30 (of course).

After installation I’m able to boot up once (with Power Central installed), with system 7.1 running Apple diagnostics and Power Demo (without problem), then after 10 minutes the system freezes. After reboot the sequence freezes again when loading Power Central. I’ve been able to get the same result with two different logic borads!

Is this a typical incompatible problem between the TwinSpark adapter and older versions of the Universal Powercache? Or is it a problem solved by moving some of the jumpers on the adapter?

Sincerely,

KTKM

 
Needs to be P33 or later. Look on the lower left side of the front of the card to see version. 

I have tried my TwinSpark with numerous Turbo 040s, P33 050 and a Diimo card and all worked. 

 
Dang! Missed that one! The manual clearly states P33!

Thanks omidimo! (If you ever want to part with a P33, P34 or Turbo 040 for that matter don’t hesitate to contact me!)  [:)] ]'>

 
Is this a TwinSpark adapter only bit of incompatibility or do I should I worry about our clone of the Daystar IIsi Adapter for my 50MHz PowerCache in the SE/30?

 
Just look at your manual! ;) Oh, still waiting on the missing pages.

pp5253.jpg.fbb68bc79f9bf666828fb2b22f89eb2c.jpg


 
Thank's, o! I'm in the clear, just checked and mine's the P33 revision.

Now if I can just clear up the /30's Gremlin infestation I should eventually be up and running. :-/

 
I'm new to the SE/30 game, didn't know they were temperamental. The Service Guides from Apple usually ens with "replace motherboard" when on gremlin extermination expeditions. ::)

Got linkage to more useful troubleshooting/repair guides?

 
ktkm,

It's a long shot, but if your PowerCache isn't the universal version, try pulling the FPU on the PowerCache and try again.  I read on a old Usenet posting (I can't seem to locate now) this was successful in the DayStar adapters.  Good luck!

 
Interesting, does the P33 version work in the SE/30 without removal of the redundant FPU?

If removal of the FPU from your PowerCache still doesn't work tor your TwinSpark adapter, I'd suggest sending it to zomb for testing with his IIsi Adapter with original and cloned GALs before shelling out beaucoups greenbacks for a P33 or better accelerator.

If/when our cloned adapters hit the streets, you may have opportunities open up for swapping your incompatible TwinSpark for any existing PowerCache adapter that might work.

@O: thanks for the reminder, still haven't run across that manual.

 
Well Stockholm is not too far away from me compared to you folks at the other side of the ocean :p

So if I finish and order a first batch of our adapters I could test the pre-P33 PowerCache if ktkm is open for lending me his PowerCache.

 
ktkm,

It's a long shot, but if your PowerCache isn't the universal version, try pulling the FPU on the PowerCache and try again.  I read on a old Usenet posting (I can't seem to locate now) this was successful in the DayStar adapters.  Good luck!
It says “Universal Powercache” on the back, but the description dosen’t match the ones in the manual, for instance the CPU is black and soldered to the board, and the FPU is socketed and black.

Intersting about the FPU removal, I’ll look it up!

Thanks!

 
Sounds to me like the P33 model might be able to auto-detect the FPU on theSE/30 bus and disable its on-board FPU. Interested to see what the SE/30 installation instructions say about the FPU on my P33?

The P44 obviously has to be able to autodetect/disable as its SMT FPU "can't" be removed.

 
Interesting, does the P33 version work in the SE/30 without removal of the redundant FPU?

If removal of the FPU from your PowerCache still doesn't work tor your TwinSpark adapter, I'd suggest sending it to zomb for testing with his IIsi Adapter with original and cloned GALs before shelling out beaucoups greenbacks for a P33 or better accelerator.

If/when our cloned adapters hit the streets, you may have opportunities open up for swapping your incompatible TwinSpark for any existing PowerCache adapter that might work.

@O: thanks for the reminder, still haven't run across that manual.
I just read about your work, looks very promising! I’m interested!

Oopsie! Missed the Stockholm shipping syndrome complication. : :)
No, problem in times like these!  [:)] ]'>

Well Stockholm is not too far away from me compared to you folks at the other side of the ocean :p

So if I finish and order a first batch of our adapters I could test the pre-P33 PowerCache if ktkm is open for lending me his PowerCache.
Bolle, where do you dwell? I’d like to help out!

Given his wannabuy post in the TP, I can't imagine him not jumping at that opportunity. [ :D ]
You imagined correctly!  [:D] ]'>

Here are some pictures!

IMG_8432.JPG

IMG_8433.JPG

 
I would say that is the P34 revision.  The sticker has just fallen off the bottom left corner.  You should be good to go with that guy.  I would also check the +5V voltage pin on the floppy connector.  If it gets too low, around 4.7V, the SE/30 will freeze.  There's a good diagram of the floppy port power pins in the Classic Mac Repair Notes on page 9 (figure 5).

 
Your card appears to be ©1992, same as my P33 which is rev P33UV where yours is P34UV. So it might be a newer version than mine? Pull that FPU and give it another go! [}:)] ]'>

edit: P33 is printed on the Silk Screen Layer of my card, so P34 would probably be screen printed too, that's how it looks to me in the manual.

 
Last edited by a moderator:
A little update:

I pulled the FPU from the board, but the problem persist. However, without the FPU and Power Central installed, the system was stable but the CPU upgrade tested insignificant. :(

 
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