History of CMOS IC(No. 7) - Riquartz

[ Front page ] [ New | Page list | Search | Recent changes | Help | | Log in ]

The low power CMOS IC [Integrated Circuit] was one of the key developments for the quartz watch.

Seiko†

RCA†

RCA were the first US manufacturer to offer CMOS chips.

81473 - Used in the 570, a very low profile ceramic package, with 3 or 4 figure date code

Hughes†

AMI†

Motorola†

SC10018F, as used in J-L Masterquartz.

Four digit date code, ie 7322 is 22nd week of 1973

Hitachi†

Supplied IC for Riquartz 510 and Casiotron 04

Cal 510 CMOS integrated circuit marked for example "7G2 841" for 2nd week of July 1977, made by Hitachi.

Example: 3B4 reads as 4th week in February of the year 1973

A Jan
B Feb
C Mar
D Apr
E May
F Jun
G Jul
H Aug
J Sep
K Oct
L Nov
M Dec

Earlier ICs could have two digit code, ie 1B for Feb 1971

OKI†

Supplied IC for Casiotron 02 marked "MSM5920 4Y32" [for Nov 1974?]

The second character of the code is the last digit of the year of manufacture, the third character of the code is the 1-9 month production of January-September, the X - October, Y - November and Z - December. Example: 9951 reads as May of the year 1979