Turbo 040 won't fit in a Mac IIx?

[ObeyDaleks]

So here's a weird one. I finally found a Daystar IIx adapter (pretty elusive, that one). I attach a Turbo 040, open up the IIx, aaand... it won't fit!! The card is too tall, i.e. the post that holds up the drive tray is in the way. I need maybe extra 5-7mm. This seems odd since the Turbo 040 is designed to work in the IIx. I guess I could cut a notch in the plastic post, but I'm just refusing to believe that they made a mistake when designing the adapter. Anybody have any idea as to what's going on here?


It fits fine in the Mac II because the adapter is angled and the card sits on top.


But in the IIx, the card is on the side. I can just BARELY fit a Powercache, but the Turbo is taller:

 

[nathall]

Not an expert on these by any means, but from the following link it appears there are four revisions of the Turbo 040, and I can tell from the photos even without an external scale reference they are all slightly different dimensions:

DayStar Turbo 040

NuBus based 040 processor upgrade card compatible with numerous models including Macintosh SE/30, Macintosh II, Macintosh IIx, Macintosh IIcx, Macintosh IIci, Macintosh IIsi (with adapter), Macintosh IIvx, Macintosh IIvi.

wiki.preterhuman.net

You appear to have the one at the very bottom which seems to be the tallest. The one directly above it, where the board edge is flush with the top of the ‘040 looks like it would probably fit a IIx.

 

[ObeyDaleks]

Not an expert on these by any means, but from the following link it appears there are four revisions of the Turbo 040, and I can tell from the photos even without an external scale reference they are all slightly different dimensions:

DayStar Turbo 040

NuBus based 040 processor upgrade card compatible with numerous models including Macintosh SE/30, Macintosh II, Macintosh IIx, Macintosh IIcx, Macintosh IIci, Macintosh IIsi (with adapter), Macintosh IIvx, Macintosh IIvi.

wiki.preterhuman.net

You appear to have the one at the very bottom which seems to be the tallest. The one directly above it, where the board edge is flush with the top of the ‘040 looks like it would probably fit a IIx.

Good call! I actually have three but they are all the same (oldest?) version - the one with the extra cache card on the back. My version definitely looks taller in the pictures. I guess I knew there were multiple versions but I didn't realize they were different sizes. I actually thought maybe they made multiple versions of the adapter and I got the wrong one. This is a relief since the adapter is actually much harder to find.

P.S. As a further confirmation, the manual that includes, among others, the IIx installation instructions, does have a picture of the newer version of the card. https://www.artmix.com/pdffiles/TurboIns_MN.pdf

 

[Unknown_K]

I put a Daystar 040 into a IIx and from what I remember it was a tight fit, but it has been a while.

 

[eharmon]

Agreed with the above. The later revisions are noticeably shorter and work in more machines.

 

[Bolle]

That's a very early adapter that came out with the PowerCache.
Once the Turbo040 came around they changed the form factor of the IIx adapter to allow for the taller Turbo040 to fit.
It looks like this:


I'm in the process of making a IIx adapter as well - boards literally arrived yesterday, so I haven't had the chance to check actual fitment, but I made them to the same spec as the original Turbo040 adapter, so I don't see why they shouldn't fit.

The later revisions are noticeably shorter and work in more machines.

The GAL based versions actually work in just the same Macs as the later smaller footprint ASIC version. There's a lot of false information on the different variants of the Turbo040 out there... it comes down to that with a proper adapter all cards will work in all machines with the proper firmware version. The hardware doesn't make a difference.

 

[ObeyDaleks]

That's a very early adapter that came out with the PowerCache.
Once the Turbo040 came around they changed the form factor of the IIx adapter to allow for the taller Turbo040 to fit.
It looks like this:
View attachment 95786

This is nuts, I don't think I've ever seen this. Even googling, the picture of this adapter does not come up anywhere.

I'm in the process of making a IIx adapter as well - boards literally arrived yesterday, so I haven't had the chance to check actual fitment, but I made them to the same spec as the original Turbo040 adapter, so I don't see why they shouldn't fit.

This is terrific news! The IIx is much more rare than the Mac II (or even IIfx), which is probably the reason the original adapters for these are basically unobtanium. I'm sure there's plenty of people who want these.

The GAL based versions actually work in just the same Macs as the later smaller footprint ASIC version. There's a lot of false information on the different variants of the Turbo040 out there... it comes down to that with a proper adapter all cards will work in all machines with the proper firmware version. The hardware doesn't make a difference.

I think you're right, for the most part. Mine have been upgraded to 4.11 firmware. But one interesting fact is that while the three cards I have look physically identical, one of them will not work in a Mac II, but works in later Macs like IIci and IIsi with an adapter. The other two cards work in fine in any Mac. I even tried swapping the rom and the cache cards between them, it made no difference. So, unless that particular card has a weird defect, there is at least one (possibly the the oldest) variant that doesn't work across all machines.

Here's a pic. It even has a factory bodge wire (I messed around with it when troubleshooting, which is why it looks kind of messy):

 

[Bolle]

Interesting... I can't make out the speed rating on the oscillator, but I guess this must be a 25MHz card.
Also there's no Daystar part number stamps on any of the GALs. Looks like you've got a very early model there indeed.

I have mapped out a few possible combination of GALs that I have seen so far from my own cards and auction pictures:



I don't actually own one of the very early 25MHz variants, so that data point is missing for me. So I could see it might actually be possible that those very old ones will only work in IIci/IIsi. I can tell that everything else that's 33MHz or faster will then be working in any machine - although one more exception just came to my mind... there was actually an adapter for the IIvi/vx/P600 type of machines. I'm not certain if it was actually needed for the Turbo040 to work in those machines at all or if it was needed to mitigate some kind of edge case that could happen.

It looks like there are 3 bus switches on the adapter just like the ones you'll find on the back of the very last generation of GAL based Turbo040s (the ones that have GAL U38 on the front)
So my assumption is that you needed this adapter for the IIvi/vx when running a Turbo040 that didn't have the bus switches already installed.