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Casio AL-2000 Technology

Electronics

Casio AL-2000
Casio AL-2000
A hybrid first-second generation machine:

  • First Generation - nearly 200 transistors and 1000 diodes provide first generation discrete logic

  • Second Generation - Hitachi SSI MOS ICs

    • Hitachi HD3103
    • Hitachi HD3104
    • Hitachi HD3106
    • Hitachi HD3107 (often substituted with Hitachi HD317)

Two Philco MSI MOS ICs contain most of the BCD adder. These chips were probably at the cutting edge of technology at that time.

  • Philco SC1771
  • Philco SC1772

Architecture, Memory & Speed

Working from the similarity to the AL-1000, the architecture is likely to be similar:

  • 14 displayed digits, 1 sign digit and one decimal position digit = 16 digit word
  • Digits encoded as 4-bit BCD, digit-serial processing over 4-bit internal bus
  • Core memory, 8 registers x 16 digits x 4 bits = 512 cores
  • @@kHz master clock, @@mS core cycle, @@mS full-number time

Construction

Five double-sided boards plug into a hand-wired backplane.

Technical Analysis

The AL-2000 appears to be an improvement of the AL-1000 with integrated circuits allowing the AL-2000 to be smaller and yet still correct many of the AL-1000’s deficiencies. Programming remains a weakness and still consists of a single linear execution of stored keycodes with no conditional branching or looping.