Nostalgia post – part 2. During the revival of my electronic kits use from my teenage years about which I blogged previously I stumbled over a 30 year old computer advertisement conveniently put on the back of one of the instruction manuals. No, we are not talking about computers as we know them today. No, this was an advertisement for a 4-bit (!) experimental computer, the Busch electronic 2090 microcomputer.
Based on a TMS-1600 processor and designed less than a decade after Intel produced their first microprocessor (the 4004) it would have been a dream for that 13 year old boy. Unbelievable nowadays when kids use "real" computers today before they even go to school. So that was my object of desire and today it feels like I would have willingly forgone 5 years of pocket money to get one. But I never got one, partly due to me not having the money to buy one myself and partly because I guess my parents had no idea why in the world they should spend money on this. Different times. Out of interest I did a bit of research of how much that Busch 2090 cost in the mid 1980's. I didn't find anything on the net at first but then I remembered that I have a few computer magazines from the 1980's in my cabinet that might contain an advertisement. And indeed I found an advertisement in the first C't magazine ever published in December 1983 from the manufacturer where the price was given as 299 DM (Deutsche Mark). With inflation and salary increases included I estimate that the price would be equivalent to what 300 Euros are worth in 2013. The magazine is available as a PDF from the publisher here. Have a look at page 26.
As can be seen in the only video on Youtube that shows the device, there's no keyboard as we know it, no screen, just a hex-input block and a 6 digit 7-segment display, 4k ROM and around half a kilobyte of RAM. Almost unfathomably little today. But it did one thing very well then and would still do it today: It shows how computers work (and not how to work with computers).
The manual that can be downloaded from the history section of the manufacturer's website teaches on only 80 pages the very basics of a computer. How does a microprocessor work, what is a bus, what's binary, what's the hexadecimal system and why it is needed, boolean logic, input and output, how does a microprocessor calculate, etc. etc. On 80 pages (including the code) and written in a way understandable for teenagers with no previous knowledge about the topic. Amazing!
Unfortunately these devices have become very rare. They were probably already rare 30 years ago as most kids probably experienced the same difficulties getting one as I did. So I keep my eyes open on eBay, perhaps I will get lucky one day. In the meantime I was wondering if there are equivalent learner kits today. Raspberry Pis are great for learning how to work WITH a computer, how to program it and to build many cool things. But it runs a full operating system, so everything is abstracted to such a level that it's difficult to use it for learning HOW a computer works. Arduino's might be better for the purpose perhaps but the way I understand the goal of that platform is that the software that comes with it again abstracts the underlying hardware to give people easy access to a device that can interact with the real world. That's great of course but again it doesn't teach people of how computers work.
When searching on my favourite web store portals I equally came up empty handed. Can it really be that today there are no computing kits for kids in their teens (or to grown ups that don't aspire to get a bachelor in computing but still want to know how a computer works) so they can learn how a CPU works and how it interacts with memory, input output devices and all the other magic!? It seems not but please prove me wrong, I'd really like to hear about it.
In the meantime I keep musing about whether perhaps an Arduino with an input/output shield, a hex keyboard and a 7-segment display combined with a software similar to what ran on the Busch 2090 could do the trick today. Open source for the enjoyment of parents and kids!?