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IIsi PowerCache TwinSlot Adapter - Cloning Project

nickpunt

Well-known member
Also a lurker happily watching the development of this. If you need a SuperMac Dual PDS adapter for IIsi or Daystar IIcx adapter to assist in your research, let me know. I don't know if they work as I've never tested them, but they look clean. I also have Micromac DiiMo IIsi / Iici adapter (same as the image you posted initially), but its presently wedged into my SE/30 - I can take higher res pics or something if you need.

Attached is image of the SuperMac adapter. 

IMG_1473.jpg

 
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Trash80toHP_Mini

NIGHT STALKER
O*M*G*!!!!! I hope I just read that right and thanks so much for emerging from the lurk zone! Let's check this situation:

GAME: You've got the DiiMO Adapter in my Illustrator Diagram with the single DIP20 GAL on board?

https://68kmla.org/forums/uploads/monthly_01_2017/post-902-0-53097100-1485883247.jpg

https://68kmla.org/forums/uploads/monthly_01_2017/post-902-0-61793700-1485896969.jpg

SET: You're saying it works in the IIsi? Hav you tried it?

MATCH: We can use a DIP Chip Clip to read all the possible I/O permutations of your GAL and re-create the logic tables without ever de-soldering it!?

THEN:

GAME OVER!!!!!!

 

nickpunt

Well-known member
It's not the SE/30 DiiMO / Artmix variant from your diagram, it's the IIsi variant. It's smaller but I'm guessing they're the same thing just differently laid out as it just has the one DIP20 GAL. I don't know if it works in the IIsi (don't have one) but seeing as it works in the SE/30 and it says its for the IIsi, my guess is it does :)

Just so you can see how it's used, attached is it wedged into my SE/30 atop an Asante MacCon+ with a right angle EuroDin adapter. Had to add a wood spacer to keep the DiiMO set in place, and has been working just fine this way. 

On a forum a while back someone mentioned that this card worked in the SE/30 and supported a Daystar Turbo 040 as well:

> I'm not rich, and I didn't have any suitable adapter for SE/30, but I found
> DayStar Turbo 040 works with "DiiMOCache Mac IIsi adapter" on SE/30.
> (I got DiiMOCache 50MHz with IIsi adapter for $10.00 or a little bit more
> on eBay(USA) several years ago. I was lucky, but it cost much more for
> shipping to JAPAN, anyway..)
> This adapter has both accelerator slot and '030 PDS slot. The only, but BIG
> problem is DiiMOCache Mac IIsi adapter does NOT fit SE/30 physically, so
> I had to move drives and cut some metal frame.
I've never used a DIP Chip Clip, is it easy to dump contents? 

Also, regarding your mystery SE/30 adapter photo at beginning of thread, I did a google reverse image search and it's an artmix prototype board for Xceed. Looks like you might be able to buy it for about $86 (9900Y) since its still listed.

IMG_8534.JPG

IMG_8660.JPG

 
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Trash80toHP_Mini

NIGHT STALKER
It's not the SE/30 DiiMO / Artmix variant from your diagram, it's the IIsi variant.
Maybe so, but it's still the SILVER BULLET!!!!!!!!!!!!!!!! [:D] ]'>

The IIsi version is really more useful anyway. Copying the PCB layout of your card is more easily adapted to the SE/30 form factor than the other way around.

Dunno how hard it's going to be to do a readout of the GAL. The security fuse is almost certainly blown, so we've gotta figure out a lashup to use something like the Rpi's or my Opi's built in I/O flexibility to brute force the responses of your GAL to all possible variations applied the inputs.

If that approach to rebuilding the logical structure of the GAL in order to clone it is determined to be workable, somebody else is going to have to work the logistics of that out. Things are moving far more quickly than I ever dreamed they might for this project. I've only gotten just about to the point of understanding why an output from a PAL or GAL might be wired right back to an input for recursive(?) processing.

If you're amenable to the suggestion, I think we need to get your board into the hands of one of our rework specialists for desoldering the chip, doing a board scan and then socketing that precious DIP IC of yours. That way we can verify the traces underneath, buzz the connections without the complication of its presence on the board and use a ZIF socket in a more conventional readout setup than just clamping a chip clip onto it to read over ribbon cables without removing any functionality of your adapter.

Dunno, this appears to be moving along wonderfully. Worst case scenario for me would be needing to get money together from somewhere to just buy a more convenient (for you) Artmix board to swap for yours. [:)] ]'>

 

nickpunt

Well-known member
I'm beginning to think that this process you're going through is very likely the same process Artmix went through to create the TwinSpark. The MicroMac adapter's chip is a GAL16V8B-10LP and the TwinSpark chip is a GAL16V8D-15LP. They're basically the same exact reprogrammable chip, the latter being a slightly newer variant and probably the one available at the time of the TwinSpark creation. The TwinSpark's main differentiator is the form factor. Besides that it just has a few resistors and capacitors that the MicroMac lacks, maybe to even out power over the longer traces. From a functional perspective, they support the same accelerators and (likely) PDS cards. 

​Isn't it reasonable to assume that the TwinSpark GAL is just a direct clone of the MicroMac IIsi GAL, with the logic board shaped in the form of the MicroMac SE/30 DiiMO? I mean, why would anyone go through the trouble of programming their own logic when there was a card from a out of business foreign company that one could just clone? Seems the skill required to clone is lower than one to DIY, and there'd be no meaningful legal implications.

The reason I ask is that I'm a bit hesitant to make any modifications to a rather rare IIsi MicroMac adapter when there's lots of TwinSparks out there that can be cloned. The IIsi adapter's compact size allows for an additional PDS card in an SE/30 beyond the one you get from the TwinSpark. E.g. I can run a Asante MacCon (+rt angle) -> DiiMO IIsi adapter -> Accelerator + add'l PDS like video, vs an TwinSpark -> Asante Accelerator + MacCon. After battling with many possible configurations (including Gamba's many diagrams) I think this may be one of the only setups that can reasonably do this.

I'm happy to have the board buzzed and I do have more hi res photos (attached, and have more) if that helps the project. I'm much more hesitant about modifications like desoldering the chip, especially since it really seems like the TwinSpark has the chip we need, and it isn't that great a loss (beyond financially) to sacrifice one of those to the cause. OTOH, if the MicroMac board were to have issues afterwards, that wouldn't be replaceable.

Does that make sense? Or am I missing something? Maybe you already knew all this :)

IMG_6953.jpg

IMG_6952.jpg

 
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Trash80toHP_Mini

NIGHT STALKER
I have the same concerns you do about your card, but we've got some really talented folks (at least one who does board level repair work for a living and one who's been entrusted with doing much the same with priceless ROM DIMMs from the fabled PEx prototypes) who might step up to the plate for this. They do surface mount work on a regular basis, thru-hole DIP tech is a cake walk by comparison.

You're exactly right, I'm doing much the same thing the fellow at Artmix probably did with the SE/30 version of your card, but copying the fruits of his labor isn't something I personally consider ethical for me to do myself. So I've intentionally taken a "clean room" approach when it comes to that card, he is is still in business after all.

Take a look at the pic in this thread over at ThinkClassic: DayStar PowerCache Adapter Family Tree. There are several interrelated threads out there aimed at cloning as many of the adapters pictured as possible. Re-creation of the DualPort IIsi pictured in that post (the later revision is featured in this thread) and then adapting it to an SE/30 form factor expansion card with a pair (at least. ;) ) of conveniently located PDS passthru connectors is but a part of the overall cloning project.

The overall PowerCache Adapter cloning project itself is a part of the impossible dream of creating a Clone of this card  .  .  .

DayStar-PowerCacheNuBusFPU.jpg

.  .  .  which, after form factor adaptation, could introduce a NuBus slot into the possible mix of cards in your SE/30. I've had a series of threads running in parallel to this one related to the NuBus in the SE/30 prospect that almost everyone with one seems to have been curious about from day one of the /30madness. If it works out, I'll have an adapter card putting a pair of NuBus Slots inside my own SE/30 along with my 50MHz 030 PowerCache accelerator.

Be that as it may, your help in winding up this chapter in the easiest possible manner would be greatly appreciated. However, if you remain uncomfortable with the prospect of desoldering and socketing the GAL on your card I understand and we can all work together in demystifying those disappeared traces by indirect means. [:)] ]'>

edit: if someone else has an Artmix card in hand, desoldering/socketing the GAL on it in order to map those traces would be just as good. The GAL is one thing, that's real work, but simply copying the traces on the DiiMO card is another thing entirely. Despite complications related to my Jesuit education, I'm not THAT much of a purist!  [}:)] ]'> 

 
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joethezombie

Well-known member
So I'm curious how does the PALs on these adapters work?  I see the PAL is connected to /BG /BGACK and /BR on the PDS and CACHE slots.   Looking at the definitions:

/BG "Bus Grant" An output signal indicating that an external device may become bus master following completion of the current processor bus cycle. 

/BGACK "Bus Grant Acknowledge" An input signal indicating that an external device has become bus master.

/BR "Bus Request" An input signal indicating that an external device wishes to become bus master.

Once the adapter and accelerator are attached to the system, how are these signals used to move processing to the accelerator?

I tried reading the pertinent sections in DCaDftMF2 and also 68030 User's Manual, but I can't quite wrap my head around it.

I guess that the PAL would need to monitor these signals from the lobo, accelerator, and PDS passthrough and grant bus appropriately?

 

Trash80toHP_Mini

NIGHT STALKER
You and me both! I hope somebody chimes in with a better explanation a/o theory, but here's mine:

Some of the lines probably need to be massaged/combined/ from their vanilla 68030 representation on the PDS in order to synthesize the IIci Cache slot's functions. Apple's docs explain why they don't classify the IIci Cache Slot as a PDS. Though Apple strongly discouraged such shenanigans, they defined the limitations involved in building a card for that slot (power being a major one) for purposes outside its intended purpose. The IIci Cache Slot can be treated as if it were a general purpose PDS within those limitations because it's a functional equivalent of a PDS.

I've been treating that slot as a "Black Box" because the actual conversion itself can't be all that big a deal. The mere existence of the IIcx and LCIII PowerCache Adapters which have no active component adaptation on the boards proves that point. Check out the summary of the info I collected in: Are there Chips on your PowerCache Adapter?

Once the PowerCache' driver (INIT?) shuts the motherboard's processor down, the PowerCache is in total control, the lines for its doing so are present on the PDS of the LCIII and on the 68030 pins in the IIcx without any of the craziness involved in getting the PowerCache to work in Macs with actual implementations of functions (SE/30 video is located in Slot $E and messes with memory in $B(??? some other slot anyway ;) ) as well, IIRC) within the memory space dedicated to Slot Manager's mapping of Slot $E or the potential for introduction of (NuBus or PDS slot expansion cards) hardware using that allotment of memory space.

The lines on the Active Components (PAL/GAL/ROM) leading to address lines on PDS passthru and the adapted IIci Cache Slot are what seem to be at issue to me. Certain combinations of hits on control and address lines on the bus appear to me to be rerouted to unused locations in the Slot Manager's memory mapping. Somewhere in DCaDftMFxe*** is an explanation that "further decoding" of the memory addressing for a slot (IIci Cache or PDS?) can allow for additional functions within(?) that slot's memory space.

Anyways, if you've gotten this far you're probably as confused about all this as I am.

Working assumption/theory:

The upshot of all this would be that the cache operations of a PowerCache card bork anything located within Slot $E memory space. That's my best guess anyway.

***Designing Cards and Drivers for the Macintosh Family x edition, there are new editions for each processor/model generation dating back to the release of the expansion slot equipped Macintoshes II and SE.

 
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Trash80toHP_Mini

NIGHT STALKER
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nickpunt

Well-known member
Oh sorry, not offended, just had a busy week and was asking around to see if anyone I knew could do it. Great to see your investigations progressing at such a rate. I am definitely open to getting this Micromac IIsi adapter buzzed so you can recreate the traces. I'm hesitant to have the chip removed and socketed, for aforementioned reasons - if there's ways to just put a clip on it to figure it out, that'd be better, or just have that done on the TwinSpark GAL.

Whats the next step? Are there people near near San Francisco that can do this, or do I need to mail it?

Also I do have that Daystar IIcx passive adapter as well if that aids in this. Some scorch marks on it (above a bad cap?) but traces look intact- can't verify though as I have no IIcx.

IMG_7026.jpg

 

Trash80toHP_Mini

NIGHT STALKER
Hey, thanks for the pic, looks like it might be yet another anomaly. Does the IIcx adapter have a socket for the MoBo's 68030 on the other side? I don't see what should be obvious evidence of the socket for it, very strange. I remembered mine being passive, but never took note of the details of the setup. I just bought the ones I could get inexpensively during Shreve's massive clearance sale in case I ever found a PowerCache or as cheap sources of connectors in the case of the passive LCIII versions.

Lately I've been hoping that the GAL on the IIx adapter will be all we need, that's another gut reaction without any real substantiation. I didn't see any obvious reason it shouldn't, but that IIcx anomaly has got me wondering a little bit about it. If you can buzz the connections for me there's no need to take/send your adapter anywhere at this time. I should work at recruitment for that end of the project, but it looks like I may have one volunteer for doing the firmware dirty work. If I'm even up to it at all, that's going to be one tough row to hoe, the more I read about it, the more I think it's best to hand that entire process off to someone competent, but it's way fun to learn about it!

If you can peek well enough from the sides to see where some of the individual traces passing underneath might be meeting/missing thruhole pads of the chip's legs that'll help a lot.

Thanks for the encouragement, it has been an exciting few days, so much so I'll be taking another step or two back to mull things over, that first fresh look proved fruitful indeed. The IIsi is such a marvelous kluge of features and odd characteristics of the Mac II line. Its parents, the SE/30 and IIci are the most curious branches of that family tree, so I guess it's no wonder I'm continually amazed by it. Gotta love that pop-up/disappearing Video Subsystem, without a monitor hooked up it's like it isn't even there!

 

nickpunt

Well-known member
No socket on the IIcx adapter, it just wires up the 68030 straight to a powercache slot. I bought it with a daystar 68030/50 board (the 'P33' labeled variety, the one that works directly in IIci). Attached is photo of other side.

Despite my strong interest in the hacks space, I'm a total electronics noob and can't do buzzing myself. But I can take photos and ship things places :D  Let me know best way to proceed.

IMG_7019.jpg

 

Trash80toHP_Mini

NIGHT STALKER
Well I guess you can! Post some pics like that of you adapter please! I need to get a notion of what it looks like and how to proceed. THX!

 

omidimo

Well-known member
Not sure if this is helpful, but I took some shots of my Stratos


 

 

 

 
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Trash80toHP_Mini

NIGHT STALKER
8-o WOW! That's incredibly helpful. I can't believe your GAL is socketed! If you could remove the GAL and determine which of the traces underneath detour and connect to its pins and which traces pop back out from it in either direction it would be a tremendous help. Buzzing the connections would be awsome!  ;D   

 

Trash80toHP_Mini

NIGHT STALKER
Dang! Spent too much time editing and hit the wrong key combo to copy that work before trying to post it.

Summary:

It would be the dots at both ends of the red traces that need to be connected to something. After that we need to buzz the rest of the signal connections on several adapters for confirmation of what the heck is going on in all these different programmable logic ICs. First step will be to test the IIx GAL on a prototyping board.

/monthly_01_2017/post-902-0-53097100-1485883247.jpg">View attachment 11533

This is not my project! I said in the beginning, I'm trying to jump start completion of Gamba and company's DayStar adapter cloning project. This iteration of that quest is an open source endeavor. I've been begging for help all along and now that it looks like we may be getting down to the nitty gritty, others are going to need to step in to take over the parts of the project that I'm not equipped or competent to do if we're going to get 'er done. :rambo:

edit: I've neglected to mention that in my GAL research, I'm pretty sure I've discovered some dirty tricks that can be used to make a GAL's logic table unrecoverable by any means. If this were a commercial venture I'd definitely use them and I'm all but certain somebody else has used them. So my ethical objections to cloning a clone of DiiMO's adaptation logic may have turned out to have had some practical considerations anyway.

DayStar didn't have any particular reason to use e'm. ;)

 
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