Zuse Graphomat Z64 (1961–1964)

The Graphomat Z64 is a pen plotter built by the computer pioneer Konrad Zuse's company from 1961 to 1964. Ninety-eight were made.¹ Graphomats drew some of the first computer graphics shown as art, by Frieder Nake in Stuttgart and Georg Nees at Siemens.^2, 3

The machine

The Z64 is a flatbed plotter: the paper lies still and the pen moves over it in both directions. An item in the Deutsches Museum archive calls it an "elektronisch gesteuerter Zeichentisch", an electronically controlled drawing table.^4, 5 According to the ZCOM Zuse-Computer-Museum in Hoyerswerda, the machine could draw in four colours and write lettering on its own. The museum presents it as the realisation of an idea Zuse had in 1945: that computers should also be able to draw.¹

The plotter did not have to stand next to the computer. A program punched the drawing into paper tape, which was carried to the plotter and read there. The pen moved in steps of 1/16 mm at up to 22.5 mm a second, and a straight line one metre long took about 45 seconds.⁶

Nake's tape

The computing centre of the Technische Hochschule Stuttgart ordered a Z64 and got unit number 9, Nake recalled; it came without software, and he was told to write it. The centre's computer was not a Zuse machine, so he wrote his programs without being able to test them, punched them on tape and took them to Zuse's headquarters. There the plotter started, then stopped after five minutes, again and again. Nake picked up the punched-out scraps of paper from the floor, glued them into chosen holes in his tape, and the drawing ran.² His programs ran on the centre's Standard Elektrik Lorenz ER56 and were drawn on the Z64, among them Hommage à Paul Klee 13/9/65 Nr. 2.⁷

Nees at Siemens

Nees was a software engineer at Siemens, and according to the Victoria and Albert Museum he was instrumental in the company buying a Graphomat. He showed his drawings at the Technische Hochschule Stuttgart in February 1965, the exhibition described in the note on Generative Computergrafik.³ ZKM in Karlsruhe holds his Achsenparalleler Irrweg (1964), written in ALGOL for a Siemens 2002 computer and drawn in ink on the Z64.⁸ His best-known plotter work is Schotter.

Mohr in Darmstadt

In early 1970 Manfred Mohr, then in Paris, got access through a friend to a Zuse flatbed plotter and an IBM 7040 at the university in Darmstadt. There he drew his program P-21, his first drawings by a mechanical pen plotter, and called it "a milestone". He does not name the model. A few months later he was drawing on a Benson plotter in Paris.⁵

Where to see one

The ZCOM Zuse-Computer-Museum in Hoyerswerda holds a Z64 with its control cabinet. Both were used in a drawing and design office in Hamburg.^1, 9 JAEV's editorial Plotter art places the Z64 among the other plotters artists have used since.