Breakfast Bytes Blogs

After leaving the title of yesterday's post in German, the obvious place to go for the next stop on the summer of computer museums is Germany.

If you ask people which was the first digital computer, the answer tends to vary with the respondent's nationality. Do computers that were never built count? Or that were built but didn't work? Do you mean electronic computers or do electromechanical computers count? What if they were programmed by re-wiring? If you pick the right definition, it is easy to make the answer be the US or the UK. But, as we will see, a strong case can be made for Germany.

The Deutsches Museum

The largest science and technology museum in the world is the Deutsches Museum in Munich. Its official name is the wonderful Deutsches Museum von Meisterwerken der Naturwissenschaft und Technik, which means pretty much what it looks like. Although I'm only going to discuss the early computers there, it is worth visiting for a whole range of fascinating topics. The flight museum is in the suburbs at Schleißheim, not far from the hotel where CDNLive EMEA is held. My first visit to the museum was in 1973 with friends on an Interail vacation as an undergraduate. Unlimited travel on all European railways cost £28 at that time (today, €493). If you think flying to Australia is a long flight, try the train from Istanbul to Venice taking three days.

Information on visiting is on the museum website (in English; also in German).

The Z3

The first functional programmable digital computer was the Zuse 3, created in 1941.It was not electronic, but electro-mechanical, containing over 3,000 relays (600 in the arithmetic unit and 2600 for the memory and control unit). The Z1 and Z2 also had some of the same features but were never fully functional. The Z3 was built as a highly secret project of the German government (during WWII). The clock cycle was 5-10Hz. It was a binary computer with a 22-bit word length.

The program was stored on punched 35mm film stock, and so it was not programmed by rewiring. The program, however, was run directly from the tape, and not stored in memory. It seems that the tape would typically be made into a loop so that the program would run repeatedly. It lacked a conditional branch. So while it is technically the first programmable computer, it lacked some features that we would consider essential today. One thing that I find surprising is that it had binary floating point. Konrad Zuse was a civil engineer, and initially he built computers not to create a computer company (which he later would), but because he wanted a tool to help him in his civil engineering projects. So it was designed from the start for scientific use, as opposed to business use.

The Z3 in the museum is apparently a replica since the original Z3 was destroyed in 1943 by Allied bombing of Berlin. Zuse had built it in his apartment and it was bigger than the doorway so could not be moved to a safer location. However, the replica was built by Zuse's company.

The Z4

Zuse's next computer was the Z4, which was built just before the end of the war. It was also relay based. It had the capability to conditionally skip instructions, which meant that it could undertake a much wider range of calculations. Only one was built, and it was used until 1959. It was the first commercially sold programmable computer that worked (apparently it was beaten by another commercial transaction but that computer never functioned).

The Z4 ran a lot faster than the Z3, with a clock cycle of about 40Hz. It could do an addition in 400ms and a multiplication in three seconds. Its floating-point performance was around 1/4 FLOPS (about 1000 operations per hour). It had a word length of 32 bits and 64 words of memory. It consumed around 4kW in operation.

In some ways, Zuse was also the creator of the first computer startup, raising money from the sale of the Z4 to ETH Zürich, and selling an license of his patents to IBM, to create Zuse-Ingenieurbüro Hopferau. Later he would found Zuse KG which would, eventually, be acquired by Siemens.

The Deutsches Technikmuseum in Berlin apparently has 12 of Zuse's machines. Details here. I have never visited, so I can't add any color of my own.

Heinz Nixdorf MuseumsForum

It turns out that the largest computer museum in the world is also in Germany, the Heinz Nixdorf MuseumsForum. It is in Paderborn, which was the headquarters of Nixdorf Computer, at one point the fourth biggest computer company in Europe, with 30,000 employees in nearly 50 countries.

I have never visiited the museum. Paderborn is roughly halfway between Hanover and Dusseldorf, which isn't really somewhere I've been near recently. When I lived in Nice and regularly had to visit Philips in Eindhoven, I would usually fly to Dusseldorf and then drive, since it was more dependable than flying to (foggy) Eindhoven via (foggy) Paris. But I've not been in that part of Germany for ages.

However, if you want to visit, then there is all the information that you need on their website. (in English; also in German, French, and Dutch).

Next Week

Even I haven't been a computer scientist long enough to have programmed any of these early German computers! But most of the computers I learned my craft as a programmer on are featured in the (Mountain View) Computer History Museum. I'll look at the first two of those next week.

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