Olympia CD101

Olympia Werke was founded in 1903 in Germany to develop and manufacture typewriters - please remember the famous "Mignon". Early in the Seventies Olympia partnered with Matsushita Electric Industrial Co., better known under their brands Panasonic Corporation or National, to stay competitive on the difficult market of electronic calculators before operations were ceased in 1991.

Matsushita introduced already in 1969 with the PANAC-12W (JE-240) their first electronic desktop calculator with 12-digit capability and Nixie tube display joining established Japanese manufacturers like Busicom, Canon, Sanyo, Sharp, Sony and Toshiba. Next important step in Matsushita's calculator line was the sleek Panasonic 1000 (JE-102) introduced in 1971 and based on seven LSI (Large Scale Integration) chips manufactured by Mitsubishi before introducing in 1972 the Panasonic 1010 (JE-1010) with just two Mitsubishi LSI chips and finally switching with the JE-801 and JE-1001 to Texas Instruments' single-chip calculator technology.

While many customers opted for Standard Products of the TMS0100 Family like the TMS0101 used with the Canon LE-80, the TMS0103 found in the Bowmar 901B or TMS0106 designed into the Radio Shack EC-2000, made Matsushita use of the flexible design concept of the TMS0100 architecture and as of today we know six Customized TMS0100 chips exclusively used with Panasonic or Olympia calculators:

Dismantling the featured Olympia CD101 Desktop Calculator manufactured in August 1973 by Matsushita in Japan reveals a compact design centered around the TMS0121 single-chip calculator circuit surrounded by many discrete components to drive the 11-digit Vacuum Fluorescent Display (VFD) assembled with individual tubes and powered by either 4 C-sized Alkaline batteries or a 220 Volts outlet.

Knowing the exceptional build quality of Matsushita's early calculators like the JE-850, this Olympia CD101 doesn't disappoint. The connector to the long-travel keyboard assembly is gold-plated, the VFD tubes are placed in a solid mounting frame and the power supply has enough headroom and does not even warm up during calculator operation.

Preparing our DCM-50A Platform to allow the Characterization of Single-Chip Calculator Circuits of the TMS0100 Family, we studied the featured Olympia CD101 calculator manufactured in August 1973. In a first step we observed with a Mixed Signal Oscilloscope (MSO) the signals at the TMS0121 Chip to verify its pin-out before disassembling the calculator completely to analyze its printed circuit board (PCB) wiring.

Confirming the pin-out of the calculator chip and reverse-engineering the keyboard matrix, we were able to fully operate the TMS0121 in our DCM-50A Platform and measure precisely the timing of its Display and Keyboard interface.

If you have additions to the above article please email: joerg@datamath.org.

© Joerg Woerner, April 14, 2024. No reprints without written permission.