Electrologica X8

Picture of the Electrologica X8 from 1964

The Electrologica X8, 1964.

After successfully releasing the Electrologica X1 the X8 was announced in 1963 and became available in 1965. Later on, stripped versions of the X8, named X2 to X5, were also introduced but never became popular. The X8 was roughly 12 times as fast as the X1 and also contained some new technologies. The Electrologica X8 looked like nothing more than a couple of gray and boring wardrobes and a terminal console and maybe some other terminal devices, like a printer.

Technical Details

The X8 is backwards compatible with the X1. The memory units of the X8 consists of at least 16384 words and maximal 262144 words. A memory cycle took around 2,5 microseconds. The X8 had three registers available of 27 bits and one extra register of 54 bits, which were all usable as index registers. Hardware support for floating point numbers, stack management and memory management was also added to the X8. Information about the implementation of the floating point arithmetics in the X8 machine is written by Dijkstra, see EWD-145[1].

The Electrologica X8 is named X8 because eventually the machine would be 8 times as fast as the Electrologica X1. Finally the X8 became 12 times as fast as the X1.[2]

The X8 was provided with a dedicated communication processor, named CHARON (Centraal Hulporgaan Regeling Overdracht Nevenapparatuur, Central Helping unit for Managing Communication with Terminal devices). This processor took control of the terminal devices in parallel with the central processor. CHARON used microprogramming and was one of the first implementations of this concept. Information about how to program the X8 machine and about the behavior of the CHARON is written by Dijkstra, see EWD-149.

Electrologica's Demise

After the X8 success story, the Electrologica N.V. company never played an important role any more in building computing machines, since cost and competition became bigger during the years. Electrologica N.V. was taken over by Philips after it went bankrupt, and eventually disappeared[3].


  1. Dijkstra, E.W. , E.W. Dijkstra Archive, , 2002  .
  2. F.A.M. Smeijers , De Eerste Nederlandse Computers, , 2007  .
  3. Nijs, G. de , Opkomst en ondergang van Electrologica, , Amsterdam, Amsterdam University, pp. 7, 07/2003.