Our first own computer!

In the 1970s, the work to be carried out was based on computations on large and powerful computers. Our experience from the Laboratory of Electromagnetic Theory at DTU was based on computations caried out at NEUCC, but the computer here was for education and scientific work only. TICRA could not use this computer unless we were in cooperation with the Laboratory of Electromagnetic Theory.

For minor calculations, Frank Jensen had a HP-35 from his part time work at Roskilde University, Denmark. This was a revolutionary scientific pocket calculator as it performed trigonometric and exponential calculations which hitherto had to be made by a slide rule. Later, everyone in TICRA got a HP pocket calculator so we could check the computations of the Fortran codes. This was valuable since debuggers did not exist at that time, and we had to include printing of the values of suitable variables at suitable places in the code, recompile and rerun in the search for errors.

However, when we had to carry out larger calculations, we rented computer time at the very fast Control Data Corporation (CDC) in Copenhagen, Denmark, where there was access to a CDC 6600 supercomputer with an impressive core memory of 128k 60 bits words located in Stockholm, Sweden. We had 24-hours access to CDC, which turned out to be convenient as we often used the late hours for our computations and then we were the only users at the terminal.

However, in 1979 TICRA purchasedits first computer, a PRIME-300 minicomputer with 196 kB RAM and 6 MB hard disc. With a ‘discount for quick decision and payment’ of 18%, the price amounted to DKK 377,000 (around EUR 50,000 at the time) which was an immense investment for our young company.

Fun fact: The 3 kilometres trip for delivering programs and data on punch cards to the CDC was made primarily on bicycle.

We could not find a picture of the PRIME 300, but here is the TICRA Team grouped around the PRIME 400 console that we purchased in 1980.