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ProtoCache1.1 - IIsi/SE/30 PowerCache Adapter Prototype

olePigeon

Well-known member
Have you tried underclocking the Turbo 040 with a slightly slower crystal?  Maybe down to 30 MHz instead of 33?  (Or 33 from 40?)

 

Von

Well-known member
The firmware on the Micron is not compatible with 040 CPUs. This still applies today as it did in the good old Gamba days ;)
That is what I thought and what I experienced when I tried SE/30 + Asante + Daystar IIsi adapter & 040 Accelerator + Micron Xceed. I tried it once and trusted what Gamba said,


SE/40etgs:
This setup would have EtherNet + DayStar Turbo 040 accelerator + Micron Xceed internal grayscale.
But, our testing has confirmed that the Xceed Color 30 video card is not compatible with the DayStar Turbo 040.
This was also verified without the EtherNet card, and using DayStar SE/30 instead of DayStar IIsi PDS adapter.



Then I saw this setup with the motherboard running outside the case (I'd love to know how you do that):

As said I decided to make a tall version as well because the IIsi Pivot can not be made to work together nicely with the Turbo040. There seems to be a timing issue that does not occur when the PowerCache is used instead of the turbo.

Problem also does not occur when the two PDS cards are connected directly to each other.

So:

MacCon->IIsi Pivot->adapter+Turbo040 = works

IIsi Pivot->MacCon->adapter+Turbo040 = works

adapter+Turbo040->IIsi Pivot->MacCon = works

adapter+Turbo040->MacCon->IIsi Pivot = works

MacCon->adapter+Turbo040->IIsi Pivot = does not work

The GAL is buffering the clock signal and introduces a really small delay which seems to be enough to throw things off for the Turbo040 as it seems to be operating on a tighter timing than the PowerCache.

And even though this...

View attachment 20865

...might look funny it is not actually useful :p

The IIsi Pivot and MacCon will still fit nicely on top of that, so no problem if you do not need to run big cards like the XCeed....
Did you happen to try:

adapter*+Turbo040->MacCon->Xceed (*where adapter is what you created or a IIsi with Accelerator/Cache slot and PDS passthrough)?

This has the the adapter and 040 fist in line on the PDS slot...

Gamba said he tried it however I didn't and am away from my machines at the moment.  I do understand the challenge of fitting this rig in the case however I am working on something that could address that.

THx

 
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Bolle

Well-known member
The Micron and 040 do not work together in any possible combination.

It hangs on a gray screen when initializing the Micron no matter if the internal or an external screen is used.

 

Trash80toHP_Mini

NIGHT STALKER
Oopsie! I misread/failed to read your question, Von. Booboo's badly in my response.

silly notions:

Are we positive it's a firmware issue and not merely a timing issue?

Has a crystal tweak for the Micron been tested? Could decoupling/massaging its timing inputs and then tweaking its outputs back into phase with the 040 card's bus timing shenanigans allow it function correctly in its own little timing bubble?

Tweaking the outputs might not even be necessary? It interfaces directly with the A/B as with its external connector, no?

Thinking here is along the lines of a NuBus card operating on a buffered asynchronous 10MHz bus. A synchronous PDS bus card is the equivalent of a bus buffered NuBus card as far as the Slot Manager is concerned. Could we take another page from the NuBus playbook and introduce a near synchronous buffered bus into the PDS world?

Sorry if this is techno-noobish babble, gotta ask em' as they come up as a learning experience if nothing else. :mellow:

 
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Bolle

Well-known member
The accelerators CPU clock is not present on the PDS connector. Everything on the PDS is synced to the 16MHz clock.

 

Von

Well-known member
The Micron and 040 do not work together in any possible combination.

It hangs on a gray screen when initializing the Micron no matter if the internal or an external screen is used.
I figured that this had been checked, thanks much for confirming!

I have a couple of threads on a possible path to a SE/40etgs where the Daystar 040 is replaced by a Carrera 040:

Need help with MicroMac Carrera040 in a SE/30
SE/40 Grayscale: Need help with a Carrera hack

User GeekDot engaged on this quest and delivered 2 revs to the Carrera CP, neither of which worked. Our thinking was that the init needed to be patched too.  Problem is that in one of these posts there was much discussion (spring/summer of 2017) and possible direction appears to have been lost in the site upgrade. Both of us have asks into the Admins to see if the missing posts can be recovered...

 

Trash80toHP_Mini

NIGHT STALKER
The accelerators CPU clock is not present on the PDS connector. Everything on the PDS is synced to the 16MHz clock.
We're not talking about the same thing, I should have said "CPUCLK"

If the Micron card is running off the SE/30's native clock signal on PDS pin A38 CPUCLK signal and the 040 card's aggressive timing on that line is what's upsetting the Micron, I've got one of my knuckledraggin' Neanderthaler tests in mind:

On your adapter, cut the Passthru's trace to A38 (CPUCLK) and jumper it to the C38 (C16M) 16MHZ reference signal that's used to get SE/30 cards to work on the IIsi's 20MHz PDS.

It's a long shot, but might be worth a try? WTH! :ph34r:

 

Trash80toHP_Mini

NIGHT STALKER
The short of it:

Got linkage to the PowerCache drivers for IIci/IIsi/SE/30 handy?

The long of it:

After wigging out on the new USPS tracking disservice, my bargain basement, untested IIci board for finally taking my long untested 50MHz PowerCache hit the bench today!

Seems to work despite a Maxell fizzle that ate away the entire positive contact in the battery holder! [:D] Can't get a startup chime on it without PRAM bat with the speaker from the IIcx, but I'm not getting one from that machine either. Gotta test with another speaker a/o bat.

Forgot about the lack of cutout for the VampireVid connector in the IIcx case. That'll be desoldered if it's the only physical incompatibility. I've got at leas three times as many VidCards as I have Macs to put them in and IIci video shouldn't happen to anybody but a writer with a Portrait Display, a DTP jockey who needs spot color on a miniscule CRT to go with a "real display" or a gamer.  [;)]

Looks like there are no ROMs on the IIci board? Boots GREAT from BMOW's SIMM/ROM image! Lovin' that acquisition. [:)]

The one time I have a chance to test the IIci Cache Card mcd sent my way I can't even find the dang thing! LOL! I've got him to thank for the PowerCache he sent along with a Mac II adapter, great guy, much missed here. You can blame him for my years of babbling about this adapter cloning project. Idling curiosity about that funky Mac II adapter with discrete CPU and MMU connections was the genesis, actually starting the string of threads came later.

 

Bolle

Well-known member
On your adapter, cut the Passthru's trace to A38 (CPUCLK) and jumper it to the C38 (C16M) 16MHZ reference signal that's used to get SE/30 cards to work on the IIsi's 20MHz PDS.
CPUCLK and C16M are the same and connected to each other already on the SE/30 logicboard.

 

Trash80toHP_Mini

NIGHT STALKER
iCrap! Cut it and add an "in phase" oscillator for a clean signal? My indecently uneducated WAG here is that the 040 is latching on the very edges of the 030 clock to the point (it jitters???) the Micron card finds it unpalatable?

 

Bunsen

Admin-Witchfinder-General
While we're in the realm of wild guesses and tilting at windmills...

What (roughly) would be involved in implementing fast RAM or cache onboard the adapter?

 

Trash80toHP_Mini

NIGHT STALKER
Cache is on the PowerCache, but Bolle doesn't think it'd be a big deal to put it on an accelerator build IIRC.

You're thinking along my line of thought when it comes to a VM RAM Disk for the 68030 PDS. I'm more interesting in doing it on a socketed upgrade card with 72 pin SIMMs similar to the SIMMspender for use in more 68030 Macs like my IIfx. The daughtercard on Bolle's Quesse board appears to be the model:

68030-VM_RAM_setup_for_SE_on_Quesse_DaughterCard.JPG

Line driver/buffering and a GAL based memory controller to generate CAS/RAS/Bank Select etc. are all on there.

Dunno where in the address map it might fit, but there's plenty reserved in every 68030 Mac that its onboard MMU might page.

 
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Great Job!!
When is ready, I'd like to buy the full size one for my SE/30.

If you already have a list, please add me.
Thank you!

Luca

 

GeekDot

Well-known member
User GeekDot engaged on this quest and delivered 2 revs to the Carrera CP, neither of which worked. Our thinking was that the init needed to be patched too.  Problem is that in one of these posts there was much discussion (spring/summer of 2017) and possible direction appears to have been lost in the site upgrade. Both of us have asks into the Admins to see if the missing posts can be recovered...
Bump ;-)

While cory and bunsen seem to have read my plea for reactivating the mentioned thread, it's still dead, Dodo, vanished, Kaputt...  :'-(  

It was sort of documentation so it's heavily missed.

The previous URL was https://68kmla.org/forums/index.php?/topic/21280-se40-grayscale-need-help-with-a-carrera-hack/?p=330470 

Thanks for helping & cheers,

Axel

 

Von

Well-known member
Bump ;-)

While cory and bunsen seem to have read my plea for reactivating the mentioned thread, it's still dead, Dodo, vanished, Kaputt...  :'-(  

It was sort of documentation so it's heavily missed.

The previous URL was https://68kmla.org/forums/index.php?/topic/21280-se40-grayscale-need-help-with-a-carrera-hack/?p=330470 

Thanks for helping & cheers,

Axel
I second the ask on recovering that thread as I just sorted out how I might this all jammed inside my SE/30 in this thread: My PDS Extension Cable...DONE

 

tt

Well-known member
Awesome development here!

I am just reading through the threads here, so it looks like the compatibility matrix hasn't changed with this board compared to a TwinSpark right?

 

Bolle

Well-known member
I was working on cloning the MacCon and had this funny idea:

https://imgur.com/a/bDyI1Jj

Why build a MacCon in original form factor that needs another adapter plugged on top of it if you can make it just one big thing and safe a few bucks on useless connectors?

Curious if this will work.

 
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