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Burroughs C3300 Technology

Electronics

Burroughs C3300
Burroughs C3300
The Burroughs 3300 is externally very similar to the Sharp Compet CS-32. Both of these are first-second generation hybrids combining early SSI ICs with extensive discrete transistor logic.

Mitsubishi M2340 bipolar quad 2-input NAND gates are the only IC used. The balance of the logic is achieved with discrete diode and transistor gates.

Architecture, Memory & Speed

  • 16 displayed digits, memory word layout to be determined
  • Digit encoding and data path architecture to be determined
  • Core memory
  • ?? kHz master clock, ?? mS core cycle, ?? mS full-number time

Construction

The chassis is a typical intricate, neat, high-quality early-generation design with many screws and fasteners.

The electronic logic is on three double sided-PCBs that are mounted in heavy steel frames and then slotted into the chassis. The PCBs have a rather anarchic layout with dense forests of on-end diodes and many long wire links. This arrangement probably helps to save space and the machine is nicely compact, but makes it very difficult to follow the circuit. There is a helpful silkscreen overlay of signal names.

The power supply in a conventional step-down transformer with series-pass regulation of logic voltages. The power supply PCB has a prominent “HEC” marking, for Hayakawa Electric Company.