Dear Tandy...This is NOT a Computer

[Cyberdragon]

What is this utter POS made of switches and lightbulbs?! By even the simplest definition, you could say a computer is an automatic machine that is reprogrammable, and this doesn't even fit that! Nothing about it is automatic, it's just manual switch logic like you'd find in your house wiring, they should have called it 'Digital Logic Kit' at best! A seventeenth century automatic spinning loom probably has more processing power than this pile o' crap, yet they have the audacity to call it a "computer"!

BURN IT FRAN! It should never have existed!

EDIT: Oh No! I just noticed it says "Science Fair" on it. If you brought this to a science fair, you would probably be disqualified.

[rrinker]

 It's hardware AND and OR logic!

I had one of those when I was a kid. I quickly went back to my 150 in one where I could build circuits that actually did something. It wasn't all that long ago that I threw mine out. Had I know I could have sent it to Fran, mine may have been missing some of the cards and inserts but the chassis was unbroken.

[ebastler]

Of course this is reprogrammable -- in the same way the ENIAC was, which undisputedly was a "computer".

@cyberdragon: Maybe you should broaden your horizon a bit? (By a decade or two? ;-)

[buck converter]

Of course this is reprogrammable -- in the same way the ENIAC was, which undisputedly was a "computer".

@cyberdragon: Maybe you should broaden your horizon a bit? (By a decade or two? ;-)

or stop by a science fair?

[Cyberdragon]

You guys are misunderstanding what this thing does, or more accurately, can't do. You can't reprogram something that is incapable of executing a set of tasks. Even vacuum tube or mechanical/electro-mechanical computers can perform sequential operations on their inputs. Even clockwork punch-card machines run sequential tasks. In this machine, the user is the one performing all the operations, it literally performs one step and that's to light the lamps (or short-circuit, which is frankly the far better option ). Manual switch logic can't perform beyond one level of logic operation without the user providing the input continuously. For sequential logic you need devices that can trigger each other automatically, something manual switches are incapable of doing. I don't know why they didn't just make a board full of small relays and a few buttons and switches, that would have been allot more useful.

[vk3yedotcom]

I had one and was also not inspired. Quickly went back to my 150-in-1 and the more fun (for me) analogue radios, electronic birds, light alarms, metronomes etc.

Something with diodes, relays, buzzers and capacitors would have allowed various latch, interlock and timing circuits.  But it would have greatly increased the cost as relays weren't cheap.   

[ebastler]

You guys are misunderstanding what this thing does, or more accurately, can't do.

Oh, I am quite aware of the limitations. I had a precursor of this "computer", and we discussed it in a neighbor thread here:
https://www.eevblog.com/forum/vintage-computing/what-was-the-very-first-computer-you-owned/msg1267920/#msg1267920
And yes, I posted it as "my first computer" with tongue slightly in cheek...

You can't reprogram something that is incapable of executing a set of tasks.

I don't subscribe to this. Yes, the the clocking and sequencing are not automated, but rather rely on a manual action of the user after each step. (Where the user action is purely "mechanical" in nature, and is directed by the output lights from the previous "clock cycle".) But this does not take away from the fact that the combination of logic equations and user steps guided by them constitutes a "program", in my book.

[Ian.M]

Compare with CARDIAC - no electronics, just sliding cardboard strips and a pencil. 

[joeqsmith]

Compare with CARDIAC - no electronics, just sliding cardboard strips and a pencil.

I had never seen this until now.  Thanks for the post.

I would assume as technology continues to change, so will our definitions.  It was not too long ago that a computer was a human that ran numbers.

[ebastler]

Compare with CARDIAC - no electronics, just sliding cardboard strips and a pencil.

Thank you very much for that link -- I had not come across these at all!
Turns out they are still available on ebay, NOS, at a not-too-outrageous price. Search for "cardiac cardboard" if you are interested...