Early
Electronic
Calculator
Sony 500 Series
Integrated Circuits

Known Devices: 501, 502, 503, 504.
Period:Late 1960s.
Source of Data: Data for these devices was derived from reverse engineering of a Sony SOBAX 2500 (1999 Nov).
Technology: Measurements suggest DTL/TTL with open-collector outputs. Given the low supply voltage though, this is not standard DTL/TTL. Although the outputs appear to be open-collector, there are no pull-up resistors used with these ICs.
Supply Voltage:+4 V.
Logic: Gate symbols are presented in accordance with
  • TRUE = high impedance or +4V
  • FALSE = low impedance to ground or 0V
Packaging: Sony 14-pin DIP. Similar to standard DIP but the distance between the two rows is slightly greater than the standard (...one can only wonder).
Notes:
  • The flip-flops in this logic family are Master/Slave JK flip-flops with the clocks for the master and slave sections kept separate.
    • C = Capture Input (Master section clock)
    • T = Toggle Input (Slave section clock)
    The state of the J/K inputs is captured when C is TRUE and T is FALSE. The Q and not-Q outputs are set in accordance with the captured state when T goes TRUE. See the comments on Japanese clocking scheme.
  • It appears these ICs can develop open inputs. In some instances these open connections may be repaired by heating the input pin with a soldering iron for 10 to 20 seconds. This observation is based on experience with two Sony SOBAX 2500 calculators. See repair notes for SOBAX 2500 calculators.
  • IC packages as viewed from above.




  Sony 500 Series
Calculators | Integrated Circuits | Displays | Simulations
EEC
2000 Aug