Commodore DAC-612 from 1969: Inside and Out

We take a look at a mostly-but-not-completely functional Commodore DAC-612 desktop calculator based upon the Casio 122 first produced in Japan in 1969; this particular unit was likely made in 1970. It uses Elfin display tubes and many components from a family of parts from NEC and Hitachi.

Excellent page from Brent Hilpert about the Commodore DAC-612: http://madrona.ca/e/eec/calcs/Commodo...
Early Electronic Calculator Technology Reference: http://madrona.ca/e/eec/index.html
Madrona Grove: http://madrona.ca/

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1962 Commodore Report: https://archive.org/details/commodore...
Elfin tube Radio Electronics article: http://www.decodesystems.com/re-elfin...
Japanese power connectors: http://www.zimmers.net/commie/docs/cb...
Casio 122 site: https://casio.ledudu.com/pockets.asp?...
Canonical List of Commodore Products: http://www.zimmers.net/commie/docs/cb...
Philco SC1772 shift registers: ​​http://madrona.ca/e/eec/ics/shiftreg....
Adrian's Digital Basement 1970s Towel shown here:    • AT&T Unix PC 7300 Model 3B1: A very c...  

Index:
0:00 Mini Commodore History
1:00 A tour around the DAC-612
2:29 About the AC power connector 163 (not quite)
3:54 Casio 122
4:33 DAC-612: What does it mean? Canonical List of Commodore Products
5:20 Power up: Odd Zeroes
6:30 Doing some calculations: Addition, Subtraction
7:30 Multiplication and Division: No longer working
9:43 Decimals & Rounding
12:10 GT (Grand Total?) and double plus
13:42 1970s Towel: Thanks Richard Pepper
14:04 Undersides
15:11 Inside: first look
16:20 Display board: Elfin tubes
17:17 Keyboard
18:23 Power supply & removing the top logic board
20:03 Examining the boards
21:16 Integrated Circuits in a can & JMOS
23:03 Philco SC1772: 48-bit shift registers
24:25 A few other JMOS ICs - madrona.ca
25:37 Thanks!