The IBM 1130 and Swedish computer art

The IBM 1130 was a small scientific computer that IBM introduced in February 1965 for schools and engineering firms.¹ In Sweden one spare 1130, with a drum plotter, became the machine on which the IBM programmer Sten Kallin made pictures with the textile designer Astrid Sampe and the artist Sture Johannesson in the late 1960s and early 1970s.^2, 3

The machine

The 1130 was a 16-bit computer. A drum plotter, the IBM 1627, could be attached.¹ The 1627 Model 1 was a CalComp 565 sold under IBM's name.⁴ For a programmer, Kallin explains, the pen could take one step in one of eight directions, along the axes or diagonally, "and nothing else".²

A computer in a cupboard

One of the 1130s at IBM's head office was left over and placed in the training department in Solna, where it stood in a small room driving the printers. In the daytime it was busy. In the evenings and at weekends Kallin could use it with a plotter he heard was "left over somewhere". He wrote practice programs for it in FORTRAN.²

Astrid Sampe. Asked for a picture for a Red Cross auction, Sampe called IBM and was put through to Kallin. He wrote a program that drew the cross many times, smaller and turned each time, with a menu where she typed the number of turns, the angle and the reduction. The pen sat loosely in its holder, so the diagonal lines came out slightly uneven, which Kallin liked. The weaving firm Almedahls printed the cross as curtain fabric;² the Art Institute of Chicago credits Computer Colonne (1975) to "Astrid Sampe with computer programmer Sten Kallin and IBM Plotter 1627".⁵

Sture Johannesson. Johannesson had an "alphabet" of three signs, a keyhole, a heart and the two laid over each other, and asked IBM for help to vary it. With Kallin at the 1130 he made INTRA, curves repeated and shifted until moiré appeared; IBM printed some as Christmas greetings to its staff three years running.^2, 3 Orrghen dates INTRA 1969–1974; the 2013 exhibition at Index in Stockholm dated their printouts 1970–1975, made on a CalComp drum plotter with a 30 cm paper roll, fed by punched cards into an 1130 without a screen.^3, 6

Other machines Swedish artists borrowed

The 1130 was one borrowed machine among several. Göran Sundqvist programmed Jan W. Morthenson's Neutron Star (1967) on a SAAB D21 belonging to the power company Skandinaviska Elverk.³ Beck & Jung worked with IBM in Malmö and got their image alphabet out on a line printer.⁷ At Lund University the colour plotter was fed by the computing centre's UNIVAC 1108.⁸ Machines of their own came later: Sture and Ann-Charlotte Johannesson got their first Apple in 1978–79, the start of Digitalteatern in Malmö.⁹ The full story is in Computer Art in Sweden, and the machines in Plotter Art, which ends with Olof Broström's Unverified Air, drawn for a pen plotter today.