Macintosh Plus with internal SyMBiotic 20 MB hard disk

[Trash80toHP_Mini]

It's too bad you're not comfortable with tearing it down for better pics. I'd love to see details of the sheet metal assembly.



The PCB underneath that air vented bend is most curious.

 

[mactjaap]

OK. I think about tearing it down. I also need to fix the disk drive. But I will take some time for this.

Didn't find anything on the Internet about this model. I even try to write old staff of SyMBiotic to get more info.

Maybe there is an old add somewhere in a magazine?

 

[mactjaap]

I got it dismanteled. I was not very diffiult, but it fit rather tight.

You now can see clearly the way all the wires are going. It also shows the big condensator like piece. It is a Bellinger-Lee L2142 (http://www.ebay.co.uk/itm/Belling-Lee-L2142-1-1A-250vac-mains-filter-chassis-mount-/400958763376)

A nice extra is that a date is stamped in: 8 FEB 1986. 

 

[PB145B]

Awesome! Thanks for the pics!

 

[Trash80toHP_Mini]

Very cool! So that makes the PCB I was curious about part of an aux. PSU for running the HDD. Where does it tap AC from the Analog Board? Looks like what must be the hot lead (Brown) is soldered to the switch connector, but I can't see where neutral (light blue) makes its connection.

 

[CC_333]

I've never seen a red battery holder like that. They're usually black!

Maybe it was replaced at some point?

c

 

[PB145B]

I'm pretty sure the European versions were red.

 

[mactjaap]

Here is a picture where the current comes from the analog board. I have drawn two red circles to show it.

 

[BadGoldEagle]

Thanks mactjaap for the pics! Apparently it's VERY similar to the Hyperdrive... Its PSU taps 120V at the power switch too. But, yours is SCSI, not MFM. The hacked Plus with the internal SCSI drive did not have a bespoke PSU. I really don't see why they added one considering that +12V and +5V are readily accessible from the Analog Board... 

My 128k (M0001P) has the red battery holder but my 1989 Plus (M0001AP) has the usual black one... I remember seeing early international boards on ebay with black battery holders but perhaps those were replaced? These things corrode themselves super easily when one forgets to remove the battery... 

 

[Trash80toHP_Mini]

The A/B in a compact Mac can barely power itself. The SE and SE/30 had draconian limits placed on power available for expansion.

 

[Joris W]

Hi BadGoldEagle and mactjaap,

I've got a Plus too, which I'd like to add a hard drive to, as when I as little, I used to have a Plus with internal HD too.

I never really found out the story behind that except I remember my parents bought it for me off some computer engineering student who wrote prolog. Perhaps he fitted the drive in there himself.

Suppose I wanted to retrofit my Plus with a SCSI HD, what would I need other than an old SCSI 3.5" drive? I do still have the floppies to boot the Mac with, which I'm pretty sure have Disk Utility (or whatever it was called then) on it.

Were you able to retrofit yours, BadGoldEagle?

 

[BadGoldEagle]

Well, my unit already had the internal drive+circuitry built in so I wouldn't exactly call this a retrofit. The 512k still has issues and I can't do much about it ATM, being stranded 500 miles away from my collection. 

alaska actually made something that allows you to plug any 50 pin SCSI device right on top of the SCSI chip. That's a really clean mod and I would totally recommend it if you want to commit to this. With the 'daughterboard' installed you'll just need a ribbon and a fan. In fact, it would be way easier to install a SCSI2SD. That way you wouldn't have to bother with the fan or HD bracket. Double sided velcro FTW and you're done. 

The main issue is, the Plus inherited a very experimental SCSI protocol. It means that it can prove tricky to get some drives working on a Plus. 

 

[Joris W]

Great answer, thanks!

I'll see if I will commit to this. But the truth is, since I have the Plus, I would like to be able to boot it and use (and accumulate) some apps without the restrictions of a mere floppy drive.

 

[BadGoldEagle]

Yeah, I get your point. My Plus doesn't see much use because of this very reason. Well, when I say Plus, should I say Pluses? I got a Plus ED (nothing fancier than a normal Plus) a year or so ago. My plan was to install this scsi helper card and a TTL video adapter (I actually have this but I have currently no way of connecting it to a modern monitor. The refresh rate's an odd one.)

Having everything tucked in nicely inside is definitely a bonus. As is, it kinda feels like the current Mac Pro. You want a better 'GPU'? Sure, here's a Scuzzygraph for you. More storage? Get an HD40. After a couple of upgrades, you'll end up with a genuine 'tower'!

 

[Jinnai]

Oh, its the 25-pin to 50-pin SCSI adapter board, I used to have one of those, but gave it away not knowing what it was! I really want one now, and idea where I can find one or how I could make one? I have a 128k upgrade card that adds a 25-pin IDC connector internally (so in this case probably 26-pin) and I don't have any drives that can use it.

 

[Joris W]

@Jinnai

If you mean the little adapter board @360alaska made to solder onto your SCSI chip, he shared his board design in this post: 





I've since had a few printed through oshpark. 

See the beginning of that thread for pictures.

 

[olePigeon]

I just thought of something.  If you could somehow get a transparent red Apple badge to replace the one on the front there, you could then pipe the LED through to the badge (it should already have a hole for removing the badge.)

Then the Apple would glow with the LED flashes.

Could probably do it with some resin and a simple clay mold.  Dang it.  Now I wanna try it.

 

[Jinnai]

@Joris W

No, I mean this one:

I really want one like that