VCF East: Before There Was Arduino, We Had Balls

Today, if you want to teach kids the art of counting to one, you’re going to drag out a computer or an iPad. Install Scratch. Break out an Arduino, or something. This is high technology to solve the simple problem of teaching ANDs and ORs, counting to 0x0F, and very basic algorithms.

At the Vintage Computer Festival East this year, System Source, proprietors of a fantastic museum of not-quite-computing equipment brought out a few of their best exhibits. These include mechanical calculators, toys from the 60s, and analog computers that are today more at home in a CS departments’ storage closet than a classroom. It’s fantastic stuff, and shows exactly how much you can learn with some very cleverly designed mechanical hardware.

System Source has a small computer museum in their offices just north of Baltimore, mostly focusing on ‘trainer’ and ‘toy’ computers. These aren’t technically computers, they’re more along the lines of digital logic trainers, designed to teach kids the difference between ANDs and ORs or XORs or NANDs. We’ve seen some of their stuff before including a great visualization of digital logic using EL wire (which was in attendance at VCF). Short of trucking down to the poor man’s Portland, though, this is the best look at the collection we’ve ever seen.

The best example of what System Source brought – that also plays into the headline of this post – is the DigiComp II. This is a recreation of a 1960s toy mechanical computer capable of addition, multiplication, subtraction, division, and counting. This cheap plastic toy was recreated in CNC plywood by Evil Mad Scientists a few years ago, and System Source had it out on display. 11mm pachinko balls flow gracefully through flip-flop registers, eventually landing on a lever connected to a rod that releases the next ball. We recently gave away an EMSL DigiComp II as a prize in the 1 kB Challenge. It’s beautiful, but certainly not the extent of the System Source collection.

Other mechanical computer toys included Dr. Nim, a toy that questions the definition of ‘computer’ as a device that plays a game called Nim, with the goal of the game is to be the last player to remove an object from a heap. By ‘programming’ Dr. Nim with a few letters, the game is unbeatable, so long as the human player always goes first.

With a Digi-Comp II, it’s only fitting that System Source would have a Digi-Comp I, a bizarre mechanical computer toy made out of plastic, wire, and a few dials.

Mechanical toy computers can only do so much, and there were a few more pieces that showed the progression of pre-microcontroller digital logic. Of note was the CES ED-Lab 700, an analog computer produced in the 1980s to teach students the fundamentals of digital logic. Included in this giant box of banana jacks is a clock with two outputs 180° out of phase with each other, flip-flops, AND, NANDs, NORs, and ORs. Also on deck was the Comdyna GP-6, a gigantic metal box designed to teach control systems and analog computing.

Nowadays we take it for granted that our microcontrollers can multiply. We have compilers and all sorts of fancy tricks to make computers do math fast, and if none of those work out we can just put a gigantic look up table in ROM. It wasn’t always like this, and yes, there are still people around who learned on these sorts of tools. It’s great seeing this hardware out in the real world, even if it is only for one weekend a year a the Vintage Computing Festival.

Filed under: classic hacks, cons