Today's kids think of the latest mobile devices when talking about "mini computers". In contrast, in the 1960s and the early 70s, a computer was always huge (like our UNIVAC mainframe), thus a 300kg computer was "mini". Early computers are well worth seeing due to their enormous size and the nice transparent auxillary devices.
There is a very important computer family that finally lead to today's (personal) computers: The development of the "Mini" computers from Digital Equipment Corporation (DEC), series PDP 8. The museum owns a complete production run from that devices: From the PDP 8 (also called Classic 8), year of manufacture 1965 to the PDP 8a (1975, this one is less important so it is located in the archive).
For further reading see the story about Rise and Fall of DIGITAL (Equipment Corporation).

Classic PDP 8

PDP 8 Classic

PDP 8 with tape deck TU 580, paper tape reader and hard disc

One of the museal highlights: The complete PDP 8 system with processor, big tape deck TU 580 (originally belongs to the PDP 5, year of manufacture 1963), punch card reader/puncher PC 01, hard disc DF 32 with immovable heads and a teletype as printer. The Classic-8 is called the world's first mass-produced "minicomputer". Without ICs or their ancestor it is a seccond-generation apparature.

DEC PDP 8I

PDP 8I

DEC's first calculator with integrated circuits was not cheap. The CPU on its own (in the middle of the picture) without periphery costed 27000$ at that time.
The main memory had a capacity of 8kB. While calculating a "bigger" problem, possibly some files (programs, data) had to be swapped on a (magnetic) tape and read in afterwards. DEC developed a very intelligent operating system (OS/8) which could work very efficiently with such few memory. It is very interesting to watch this computer working.

If you have not yet seen such a computer, you should know that it is more than 2m high (with plotter) and has a weight of more than 300 kg.

The periphery constists of 2 x TU 55 (tape drives), PC 04 (high speed paper tape reader), Calcomp 563 plotter (at the top) and of course a teletype (not in the picture).

LAB 8e

Lab 8e, PDP 8e

Successor of the PDP8i was the PDP8e (1970). This computer had already an internal bus system. So you could easily attach any periphery with interface cards. This feature made the "Mini"computer all-purpose. This Computer type was offered with diverse A/D- and D/A-converters and connection facilities as laboratory computer for analogue devices (shown in the picture). The periphery is:

  • VR 12 (oscilloscope display)
  • PC 04 (High speed paper tape reader/puncher)
  • 3 x TU 56 (double tape drive)
  • A/D- and D/A-converter

WANG 2200 with bulky peripheral hardware

Furthermore the first system that looks like a today's computer is connected: WANG 2200, year of manufacture 1973. The computer with so much peripheral devices is propably unique in Germany. The periphery: paper tape reader, reader for stacked cards, 8-inch triple disc drive, disc system with 38cm big disks (the device has a weight of 100kg and costed 24.000,- DM whereas it only saved 5MB), special basic-keyboard, etc.

WANG quickly recognized that the future of computers needed screens. However the concurrent HP built his computers only with a single LED display until 1975.

Wang 2200

The first personal computer was also build by WANG: PCS II (1975). The first PC that was affordable for everybody was the PET 2001 from Commodore. It came on the market in 1977 and was as cheap as a today's PC but saved 8kB and had decent applications. Many more Homepcomputer followed, the market got out of hand and therewith the collection of computers ends.

See further details at the tabular overview of mid range data processing equipment and proffessional early computers.