Help to ID this Altair?

[Curto]

I am in the process of obtaining this Altair from the estate of a friend's relative. Unfortunately the machine is current in another state and we do not have immediate access to it. This photo is the only one we currently have.

Based upon the graphics I would believe this is an early version. But I am bothered by the lack of the chrome strip and Mits/Altair badging. Is this possibly an early kit, or has the badging gone missing, or have any other thoughts. The graphics look consistent the the "early" computer on Mike Douglas' deramp.com page.

I am looking forward to a personal inspection. Just wondering what the experts think. Sorry for lack of better photo and details.

Thanks,

Curt

[AltairClone]

Yes, the silkscreen style indicates it’s an earlier model. The missing nameplate is just that - missing - it’s not something that was added only for later models.

A rear pic could help with dating as well based on whether there is an internal radius on the DB25 cutouts. Earliest card guides were natural nylon colored instead of blue/green.

Mike D

[Curto]

Thanks Mike.

This almost went into the trash, fortunately it was saved. It has been promised to me. I either need to be patient for it to make it was to me, or I need to make a road trip to Phoenix. It might be worth the drive!

[Curto]

I know this forum is for clones and such, but I don't know of another forum with as many knoledgeable people. I received the Altair as a gift today. It is n early one, with a Rev 0 CPU and White porcelain 8080. I can't make sense of the date code on the CPU, does anyone have any ideas?

There are a fair share of "bodges" that I will try to undo, Also came with two "aftermarket 4K memory cards, and a partially completed tape interface. Motherboard does not appear original.

The front panel is the early design, but is missing the name badge. Does anyone know of a source for a replacement or reporduction?

I need to come up with a plan for first power. and see if it will rn. Any advice welcomed.

[Curto]

Attachements did not take on original post. Including now....

[Curto]

Additional photos

[Curto]

Memoiry and Tape interface photos

[Wayne Parham]

That is one sweet machine. I absolutely love it!

The older power supplies are incredibly easy to maintain. Just transformers, rectifiers and capacitors. I would expect all the electrolytic capacitors to be weak, so it might be worth replacing them blind. Beyond that, just check for AC output from each transformer secondary and DC outputs from the rectifiers.

As for the rest of the system, having a working clone will help immensely. You can swap known good boards into the original Altair, or test unknown original boards by installing them into your clone.

[Curto]

Unfortunately I don't have a working clone. Although I have one that is 90% complete that I started to assemble maybe two two years ago.

I was thinking of trying to isolate the capacitors and reform them with a bench power supply. But maybe you are right and just replace.

How much damage would I risk if I pulled all the card and just turned it on? Seems worst could happen is pop a capacitor and blow a fuse. Anyone have thoughts?

[Wayne Parham]

I would do two things first:

1. Measure across each supply's output with a DVM, with respect for polarity. So for example, on the 8v line, connect the DVM's positive lead to the positive 8v line, and the DVM's negative lead to ground. If any of them show low impedance, don't power on. Find the reason and repair it first.

2. Measure each rectifier. If any diodes are shorted, don't power on. Replace the rectifiers first.

if all measures OK, I'd be comfortable to power on. Measure the output voltages.