A Tour of the Computer Technology Collection Erlangen

Dr. Rainer Ulrich: "Everyone is introduced to computing aids when they start school. My generation had to cut counting tiles like these out of cardboard and color them in ourselves."

Dr. Rainer Ulrich: "No comment, that was before my time."

Dr. Rainer Ulrich: "I’m going to risk going against the flow here: relays are more compact and less delicate than electron tubes, but SIGNIFICANTLY slower."

Dr. Rainer Ulrich: "In my childhood tubes were used as amplifiers in radios and televisions, not as circuits like in computers. Back then they were very sensitive to vibration and would simply burn out from time to time."

Dr. Rainer Ulrich: "Earlier forms were marketed as “featuring 11 transistors.” You need thousands to make a computer. They were soldered individually onto boards; later the switch was made to a modular design."

Dr. Rainer Ulrich: "The horizontal and vertical wires are the writing wires, and the wire that passes through all the cores is the reading wire. The memory depicted in the image has an incredible 64 bytes of capacity!"

Dr. Rainer Ulrich: "This CPU had some 5000 transistors on a chip with an area of 10 mm². It was used in a great many home and personal computers. Compared to Intel’s 8080, the Z80 was better integrated, required only one operating voltage and had many useful additional commands and registries. It was able to run 8080 computer code without modification. The Z80 is still around today as a functional element for field-programmable gate arrays (FPGAs) or as a CMOS variant."

Dr. Rainer Ulrich: "The image shows a magnetic drum memory, an early predecessor of the magnetic disk."

Dr. Rainer Ulrich: "Hard drives used to be large, noisy and expensive. Should there be a sudden loss of power, there was always the danger that the read-and-write head would land on the disk and cause damage. Before turning off such disks, you always had to first move the heads to their resting position. I remember once there was a small fire here at RRZE. An operator could be seen coolly executing the shutdown sequence, shutting off the power and only then grabbing the fire extinguisher to fight the fire."

Dr. Rainer Ulrich: »When reading and writing, the tapes didn’t run at a constant speed but instead tended to jerk along. To prevent the tape from tearing, there were tape loops that were drawn in using negative pressure. Once when reading my tape, the vacuum collapsed, tearing the tape in several places and rendering it unusable. I’m just glad I had a backup.«

Dr. Rainer Ulrich: "Back in 1978, when I did my first programming course at RRZE, we were still making punched cards. Each card represented a line of programming. If you made a mistake, you had to start all over again – you couldn’t “unpunch” a hole. But some of us figured out that you could copy the card up to the error and then continue. You could number the punched cards in the final column, which was very practical if the operator was careless when inserting the cards and dropped them all."

Dr. Rainer Ulrich: "I never worked with targeting computers."

Dr. Rainer Ulrich: "In 1974, a school club I belonged to had a programmable computer made by Diehl. We used nested intervals to calculate pi. Every couple of minutes, the printing mechanism would rattle, indicating another iteration was complete. After five days of continuous operation, the power adapter died. At that point, we had calculated pi to no more than ten correct digits."

Dr. Rainer Ulrich: "I never had a calculator watch – I wasn’t nerd enough for that."

Dr. Rainer Ulrich: "The Commodore 64. This came out in 1982 and you had to connect it to your TV’s aerial socket. Using the BASIC programming language and block graphics, you could also program games. You then saved what you programmed onto an audio cassette using an external drive. And if you willing to spend some money, you could get a reader for 5¼-inch disks."

Dr. Rainer Ulrich: "The IBM PS/2 featured a 32-bit processor and a hard drive that was massive for its time. The starter model shown here was actually a wolf in sheep’s clothing: it had just a 16-bit processor. The VGA graphics offering a resolution of 640 x 480 pixels and 256 colors was state of the art at the time. Due to flaws in its hardware compatibility with older versions, the PS/2 series was not a commercial success and signaled IBM’s withdrawal from the PC business."

Dr. Rainer Ulrich: "Atari computers could make music. Even at the time I thought the “tunes” were really annoying, but with just 8 bits it was never going to produce anything spectacular."

Dr. Rainer Ulrich: "CP/M systems with 8-bit processors had been around for some time before IBM brought out the first PC in 1981. It featured an 8088 16-bit processor and two floppy disk drives. The monitor displayed green characters on a black background; full color cost extra."

Dr. Rainer Ulrich: "The 3300 was no longer in use by the time I started at RRZE in the late 1970s. At that time, RRZE had a Cyber 172 that was later upgraded to a Cyber 173. The architecture was still based on 60-bit words. A word could store a floating-point value or, using CDC’s own 6/12 display code, either ten capital letters or five lowercase letters. CDC didn’t yet have bytes or ASCII coding."

Dr. Rainer Ulrich: "RRZE used a TR440 made by Telefunken that was the only mainframe in the series to be equipped with three processors. In contrast to Cyber, here the operating language was all German, which meant that the TR440 used GIB KOMMANDO to communicate with the terminal. A punched tape was used to boot up the TR440 after it had been completely shut down. The tape was kept in a specific place for emergencies."

Dr. Rainer Ulrich: "The Z23 was way before my time. For a long time, I didn’t know that Erlangen had such a dinosaur. However, it was never housed at RRZE, but at the mathematics institute on Bismarckstrasse."