Casio personal-mini teardown in pictures

Today’s teardown subject is another vintage find: a 1974 Casio Personal-Mini.

Still in the original box

$19.95 from a formerly well-known department store

Oddly enough the packaging foam is still good

It’s alive

Hmm, I bet it’s been more than 20 days since purchase

They got it right about growing number of Casio owners

0.18Watts? You can fly to the moon on less!

2 AAs is nice, though they kinda had to go that way due to power consumption

Interesting board to board interface with soldered pins. Probably good for a couple bends.

TDK CD-14202- is that a Boost converter for the display? It’s gotta be since I see no inductors/power transistors on the board.

Going around the converter pins with a scope, I see a few voltage rails, interestingly enough all negative relative to the battery negative terminal: -6.5V, -18V, -23.5V

NEC uPD178C

Along the same line, notice color coding of the battery wires: Red is Negative, White is Positive:

And some more closeups of the VFD:

 

Slow thinking video

To illustrate how this thing behaves, I made a short video. Let’s just say it takes its time thinking

User manual

And here are some shots of the user manual:

Cover

Pages 2-3

Pages 4-5

Pages 6-7

Pages 8-9

Pages 10-11

 

One thought on “Casio personal-mini teardown in pictures

  1. Pingback: Teardown of 1970s Casio personal-mini Electronic Calculator with Vacuum Fluorescent Display « Adafruit Industries – Makers, hackers, artists, designers and engineers!

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