APEXC

An All Purpose Electronic X - Ray Computer ( APEXC ) is an early series of simple structured computers that have been developed since 1952 by Andrew D. Booth at Birkbeck College in London. Since 1943, he conducted research in the field of crystal structure analysis. There were various models and the X in the name was in subsequent models replaced by a different letter. Thus one speaks of the APEC series.

Models

  • APEXC (London, 1952, later developed ), operation by punched cards
  • APENC ( N for Norway, Oslo ), ditto
  • APEHC from H ( Hollerith ), operation by teletype (tape )
  • APERC (R for rayon)
  • UCC (University College, London, 1956)
  • MAC (Magnetic Automatic Calculator, 1955)
  • HEC - 1 HEC 4 ( Hollerith Electronic Computer, from about 1951 to 1955 )

Description

The description applies to the APEXC ( for documents from 1957 ).

The APEXC had 32 magnetic drum memory, but neither RAM nor ROM. To simplify both all the commands, and operators were 32 bits long. The memory addresses have a length of 10 bits.

Since there was not the usual program counter (PC), the starting address of the next instruction in the instructions contained with. There were only 15 commands.

Served to enter a keyboard with 32 keys or paper tape. The issue was made on a printer or also by paper tape.

Emulation

The APEXC is supported by the emulator MESS.

Predecessor

The APEXC was not the first computer, the Andrew Donald Booth created. After the ARC (Automatic Relay Computer, 1947-1949 ), he developed the 1949 SEC (Simple Electronic Computer ).

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