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Fujitsu serial number date codes



Fujitsu used multiple serial number formats. The “main sequence” format appears to be as follows:


The positions have the following interpretations:

Year of production (A–Z); see under examples below
Month of production (0–9, X–Z); see table below
Serial digits (four up to around 1984, and five from around 1985 onwards)
A suffix letter, not explained; often “t”, but “e” has also been seen

The year is represented with a single character, using every letter of the alphabet, and wrapping around from Z back to A in 1985. It has been confirmed for the year range 1982–2005. See 富士通の板バネ式メカニカルキーボードについてのまとめページ -- 各種考察 for more details.

The month codes are as follows:

Letter Month
1 January
2 February
3 March
4 April
5 May
6 June
7 July
8 August
9 September
X October
Y November
Z December

Internal and external serial numbers

Many Fujitsu keyboards use separate serial numbers internally and externally. In these cases, the main sequence serial number is recorded on the internal label affixed to the PCB. Where there is only an external serial number, this may also follow the main sequence (as with FKB4700 models), but often it does not. External serial numbers may use a prefix letter and still not match. A number of mismatching examples could be found on rzwv’s site, but that has since been deleted, along with all the serial numbers. The mismatching examples tend to be membrane keyboards.


The confirmed date range for the main sequence so far is given below.

Additional examples are given at 富士通の板バネ式メカニカルキーボードについてのまとめページ -- 製品データベース, although there are no photos of the dates (only the serial numbers), so they are not listed below.

Prefix Year Keyboard Switch External serial Internal serial
X 1982 Fujitsu Micro 8 (“jpspace”) (ICs are dated late 81) FES-360 X29296
unknown (ICs are dated late 81/start of 82) FES-360 11820381X30616
Fujitsu Micro 16s keyboard DIN-compliant dual-discrete leaf spring XX0005X90005
Y 1983 Epson Q703C-AA (HaaTa) Dual-discrete leaf spring 049989Y55690
Z 1984 Sony OA-S3400 keyboard FES-4 Z53677 t
A 1985 Fujitsu FM77AV keyboard (“jpspace”) Semi-discrete DIN leaf spring AZ11755
B 1986
C 1987
D 1988 Fujitsu FMR30KB501 (MouseFan) DIN-compliant dual-discrete leaf spring P8Y03855DY03767t
1988 Fujitsu FMR-30BX keyboard (Kiyoto) Non-discrete membrane leaf spring D202053
E 1989 MAI VDT keyboard Non-discrete membrane leaf spring E201649
F 1990
G 1991
H 1992 Triumph FKB4700 (klikkyklik) Peerless type 2 H1390872
1992 Escom FKB4804-103 (niubio) Plug and toilet H7075277
I 1993 My own unbranded FKB4700 Peerless type 2 I6005425
J 1994 Fujitsu OAKB-406 (MouseFan) DIN-compliant dual-discrete leaf spring 175835J600023t
K 1995 Fujitsu FMV-KB211 (sandy55) DIN-compliant dual-discrete leaf spring 34239 02BKZ22648t
L 1996 Fujitsu F7956KB1 (“jpspace”) Post-Peerless 1479+L801859L801888e
M 1997 Fujitsu FKB8726-353 (niubio) Dome with slider M9058886
N 1998
O 1999
P 2000 Fujitsu FKB4725-501 (rzwv) Peerless type 2 PZ294887