The Electrologica X1 is a transistorised computer designed in the Netherlands in 1958. Only around 30 machines were built. It was also one of the first European computers to use Interrupts.

Bram J Loopstra and Carel S. Scholtenare are widely regarded as the Designers of the Electrologica X1 Computer. These pictures show the handwritten notes Mr Loopstra used for reference when he gave a talk in Cambridge, about the newly completed X1 Computer. The hand written notes are in Dutch and are dated 27 November 1958. It’s use of innovative Transistorised Circuitry was at the leading edge of computer design back in the late fifties, so any lecture giving an incite into the construction and computer architectural techniques of the X1, would have been very well received.

The X1 computer also has the distinction of being the first computer to use the Algol 60 compiler (ALGOrithmic Language 1960), implemented by E W Dijkstra and Jaap A. Zonneveld (Translated to English).

The Colloquium Talk was published in Vol 2 Issue 1 (1959) of The Computer Journal and is available free online through their website.