Took a gamble on a Mac Plus and SE that appeared to have accelerator cards...

[Mighty Jabba]

While browsing eBay on two separate days I found a Mac Plus and a Mac SE that both seemed to have accelerator cards installed. The sellers didn't mention it in either case and seemed to know nothing about it, so it while I didn't pay too much for them, it was a bit of a gamble. Still, I'm kind of fascinated about this kind of modification, so I decided to see what I would end up getting. I'd like to get a little advice about what to do with them. So far, only the Plus has arrived. As you can see, there is a "68030 Power/Total Systems" badge on the front, and a sticker on the back saying that you can't just slide out the logic board as you might normally do, and it also mentions the "Gemini 020/030 card manual" so I'm assuming that the card is called the Gemini from Total Systems. There is also what appears to be a SCSI port in the battery compartment. (I removed a battery that was just starting to corrode.) It came with zero software or accessories beyond the power cable.



The internal floppy appears to be borked in some way -- the mechanism is in the wrong position to receive a disk, and the machine wouldn't even boot from my Floppy EMU while the internal floppy cable was connected. But it did boot just fine when I disconnected it. It shows that it has 4MB of RAM, but in terms of speed, I can't say that it feels any faster than my other Plus, but I haven't done any real tests. It's certainly no speed demon. Opening it up revealed that there was indeed an accelerator board inside.



There is something mounted on top of the floppy drive in a way that makes it necessary to remove everything in order to get at the floppy. I'm pretty reluctant to take everything out just to get at the floppy, but is there anything I could try to fix it with it still installed?



Can anyone tell what is mounted here? I wondered about the possibility of a hard disk, but I think it's some other sort of card.



They also installed a fan.



I'm curious if I'm actually getting any additional speed from the accelerator as it is or not. Worst case scenario, I guess I have a Plus with 4MB of RAM and a SCSI port, so that's pretty cool. Any advice about what I should do regarding the software? Keep in mind that I can only have one thing attached at once (external floppy or the Floppy EMU -- unfortunately I have no SCSI devices but am planning to get an SD2SCSI at some point).

 

[Mighty Jabba]

Quick update: I did manage to get the floppy mechanism back into position so that it would accept a disk, and it does function, but (of course) the eject mechanism appears to be shot. The weird thing is that when I tried to boot it with both the internal floppy drive cable and an external floppy connected, it made the boot chime and then just never stopped. Is that a known issue of some kind?

 

[Crutch]

That’s a great accelerator. I have one too. The thing mounted behind the floppy is a dedicated power supply for your accelerator board. It’s wired directly to AC power at the Mac Plus switch using test clips so it puts zero drain on your original analog board. 

To get the speed benefit and have the system recognize it as an 030 you need to run the proper drivers. GemStart is probably the best choice. It’s available on the Garden and elsewhere. It will absolutely fly. I can probably help if you need assistance configuring it. 

By the way, your Plus has a stock SCSI port so you don’t really need that SCSI out thru the battery compartment. That’s a great feature if you want to install this board as a fully removable upgrade on a 128k though (which is what I did)!  

 

[Mighty Jabba]

Great, I'm glad to hear from someone who has one. Can you explain what exactly I need to do to take advantage of the speed increase? Where would I put the Gemstart 2.1 control panel and does it matter what OS version I use? Is it possible to do add it to a boot floppy?

 

[Bolle]

The accelerator should run without any drivers but not all features will work. I see you have RAM and cache on yours so a driver will be needed to activate those.

Depending on how much RAM you got installed you might want to look into Connectix CompactVirtual as well to use the additional RAM. You need a hard drive to boot from and install the software though for that.

If you only want to install the accelerator driver that will fit on a floppy disk probably.

Gemstart just goes into the system folder on System 6 or into the control panels folder in System 7.

 

[Mighty Jabba]

I've been having some issues trying to get this to work. When I tried adding Gemstart 2.1 to the system folder of my emulated hard disk on the Floppy EMU, it hangs at the "Welcome to Macintosh" screen, and the Floppy EMU gives me an error on the screen about a "changed write state" (if I recall correctly). So I tried making a boot floppy, and then I get an error after the very cute Mac with sunglasses animation for Gemstart. It either says that the Finder is busy or damaged, or that there is no coprocessor installed (seemly randomly). The bizarre thing is that I actually got it to work once, and I have no idea why! This is all booting into System 6 with Gemstart 2.1. I don't have a way to boot this machine using System 7 right now, so I'm wondering if maybe my board is somehow incompatible with Gemstart 2.1 and needs Gemstart 3.0 instead, but that doesn't explain why it worked once. I will say, that while I had it booted, it did seem very nice and fast, although I didn't have much of anything on the boot disk that I could test it with.

 

[Trash80toHP_Mini]

.  .  .  your Plus has a stock SCSI port so you don’t really need that SCSI out thru the battery compartment. That’s a great feature if you want to install this board as a fully removable upgrade on a 128k though (which is what I did)

But the Plus has no internal SCSI connector. Does that battery door connector's ribbon cable hook up to the accelerator? If so, you'd have two SCSI Controllers/Chains when it's installed in a Plus? It almost looks to me like an internal HDD might be looped back from the external SCSI Port using that cable setup.  [}] There's plenty of room for mounting a hard drive on the backside of that PSU bracket and it looks oversized for powering an accelerator alone. Interesting sheet metal, what does the wiring setup look like?

 

[Mighty Jabba]

But the Plus has no internal SCSI connector. Does that battery door connector's ribbon cable hook up to the accelerator?

The battery door ribbon cable connects to the accelerator board on the bottom left, right above the chip that says "LOGIC" on it. There are a lot of unused connectors on this board, I noticed.

 

[Trash80toHP_Mini]

Does the aux. PSU have a MOLEX power connector?

 

[Mighty Jabba]

Here is a better shot I took of the power supply from the bottom. Not sure about the connectors.

 

[Crutch]

@Trash80toHP_Mini you can indeed loop back an internal HDD from that connector. I have done it on my 128k! Mounted to the back of the PSU just as you suggest. The best thing is, unlike the stock Plus SCSI bus, this board’s SCSI bus provides term power so I can power my internal SCSI2SD directly from the bus. It is awesome. I’ll post pictures sometime but it’s in pieces on my bench right now. 

... also if I recall it disabled the motherboard SCSI when installed on a Plus, now that I think about it. Not sure I’m remembering correctly though. 

 

[Crutch]

@Mighty Jabba yeah it’s finicky to set up the first time. I’ve had similar problems. It actually looks like it’s flaking after loading the driver properly. I assume you are running 6.0.8 or similar with NO other extensions? I’ve actually never tried booting with the accelerator from floppy before. 

(By the way, you indeed don’t have an FPU. You should pick up a cheap 68882 on eBay and pop it into that socket on the board! Still, it should run fine without.)

@Bolle hmm, my Gemini 020/030 feels slow as molasses - basically unaccelerated - when I run it without the driver. I don’t understand why. Does the cache make most of the difference? I found the drivers make a massive massive difference even to mundane things like the Apple menu populating. 

 

[Mighty Jabba]

@Mighty Jabba yeah it’s finicky to set up the first time. I’ve had similar problems. It actually looks like it’s flaking after loading the driver properly. I assume you are running 6.0.8 or similar with NO other extensions? I’ve actually never tried booting with the accelerator from floppy before. 

Yes, I just wanted to see it run with a barebones system folder to make sure it was working, and also because my Floppy Emu doesn’t seem to play nice with the Gemstart extension I am limited to what I can fit on a floppy. I went ahead and ordered the external version of SCSI2SD, which I hope will allow me to actually run a “real” system, and probably System 7.x.  What version of the OS and Gemstart are you using with yours? Interesting about the coprocessor. I’ll have to order one. 

 

[LaPorta]

As far as the coprocessor error, that could possibly be bogus. When the system software cannot find an appropriate code, it defaults to the last code in its list...which is the coprocessor error. So there may be something else going on.

As for the floppy, there can be a few things going on. The “disk in” sensor may be stuck down, and the Plus is the attempting to forever eject a disk that isn’t there, causing the error you described. I’d check that first.

 

[Mighty Jabba]

Yes I don’t really think the errors are accurate, but of course something is going wrong. In any case a coprocessor looks to be extremely cheap so I may pick one up.

As for the floppy, although I was able to get it working, I have tried several times and the machine won’t start up at all if I have the internal floppy cable connected and also something attached to the external floppy port (either an external floppy or Floppy Emu). I just get a garbled screen. This is another reason I want to try a virtual SCSI hard disk.

 

[LaPorta]

One way to really sort all of this out would be to remove all of the accelerator etc. parts and se what happens.

 

[joshc]

This is a freaking cool Plus!! That must be pretty rare, definitely worth keeping it. I did not know you could get accelerators like that for the Plus.

Accelerators tend to cause havoc with the HD20 support on the Floppy Emu, so it's not supported AFAIK.

My SE/30 has a Daystar accelerator and I did manage to get HD20 support working with my Floppy Emu to boot my custom disk image, so it's possible that some work.

 

[Crutch]

I’m running GemStart 3 with 7.0.1.  I think that might be the latest supported version of System 7 but that’s from memory, I may have just stuck to that version so the Plus doesn’t slow down.  I will put everything together this weekend and run some tests - see if I can get it to boot from a floppy running 6.0.8 with GemStart 2.1.  I know that it boots fine from my (real) HD20 running 6.0.8.  I love the sound of that HD20 ...

 

[Trash80toHP_Mini]

@Trash80toHP_Mini you can indeed loop back an internal HDD from that connector. I have done it on my 128k! Mounted to the back of the PSU just as you suggest. The best thing is, unlike the stock Plus SCSI bus, this board’s SCSI bus provides term power so I can power my internal SCSI2SD directly from the bus. It is awesome. I’ll post pictures sometime but it’s in pieces on my bench right now. 

Very cool, I'd love to see pics of your setup, Is there any provision on the aux. PSU for installing a hard drive? If not, a Y-cable would likely have been part of the HDD installation kit? The four holes on the bracket look just about perfect for mounting a 3.5" HDD sled horizontally? The larger holes at the top look to be for thru bolts. If the smaller holes on the bottom are tapped for machine screws, they almost certainly planned for internal 3.5" HDD installation.

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Having it in pieces on the bench makes for a great photo op. []

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Sheet metal bracket's mounting bolts have nuts on the bottom side so it's installed and in place when the Logic Board/Accelerator is slid into place. Looks like it may be a royal PITA to remove/install the A/B connector?