The solution

It is a CES Industries Ed-Lab Microcomputer Lab model # 804.

That was a mouthful. It was made in 1982 (that's 30 years old!, for those math impaired), and was based on a Franklin Ace 1000 microcomputer, itself a clone of the Apple ][ Plus, but with an interesting enhancement: lower case support for the display and a caps lock / shift key that worked. It also had a full keypad.

If you strip away the special expansion card and the fancy case, it was pretty close to the Apple ][ some of you might have played with in the early 80s. I remember doing conversions to HEX code from 6502 assembler by hand, and typing that straight into the monitor (that was the call -151 reference on hint #2). And one thing that was extremely cool with computers from that era: instant on. Power on, hit break / reset and start coding right away. Of course, back then Python wasn't even thought of, so at the prompt, it was the Basic programming language that was king. And we had no choice but to understand the hardware and the software to really use these to the full. Thank you, Woz.

 

So who got it right?

Bob Rosenbloom sent the following: "ED LAB microcomputer training systems with a Franklin motherboard and video card."

I asked how he figured it out and he said:

"I've had them in the past. The banana jacks gave it away. I still have many of their analog and digital trainers, including one based on the Intel 8085."

However, the first (and only) to identify correctly the correct motherboard (Franklin Ace), even before seing the innards was ukscone on the Raspberrypi.org forum. And the first to correctly identify the specific Ace model was LC, who left a comment on hint #4.

It was quite interesting to see the various guesses and the interest this topic stirred. This post wraps it all up.

The recap

If you want to review all the hints:


Hint#1

Hint#2
 
Hint#3

Hint#4
 
Hint#5

In a future post, I'll talk about what I had to do to make it operational again, and what I still have to do, such as fixing the video modulator board / 80 column card (to remove the vertical lines) and fix the case itself. Another interesting story that needs to be told also is that of the Franklin computer itself. As for CES, I'm still researching that part.