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Calculator Watches · Volume 3

The Data Bank Years, 1984–2026

In January 1984 Casio put a telephone book on the wrist. The Data Bank turned the calculator watch from an engineer’s gadget into a mass-market one, and for fifteen years it grew more capable every year, while Seiko and Timex tried to go further and make the watch a terminal for a computer. Then the mobile phone took over its job, and the calculator watch settled into the role it has now: a cheap, durable, slightly ironic classic.

3.1 The first Data Bank

Casio’s corporate history records that “the Databank Telememo 10 (CD-40) was released in January 1984”. It stored ten entries of up to sixteen letters or numerals, telephone numbers with a name, and it “sold six million units in the five years after release”. Wikipedia dates the CD-40 and its companion CD-401 to 1983; Casio’s own pages say 1984. Its heritage page adds that the name Data Bank “came to be synonymous with the multifunction digital watch”.

Figure 1 — A Casio CD-401 Data Bank, companion to the first Data Bank of 1984, with its keys above and below the display.
Figure 1 — A Casio CD-401 Data Bank, companion to the first Data Bank of 1984, with its keys above and below the display. — Photo: Adalbert1111, Wikimedia Commons, CC BY-SA 4.0.

Casio pushed in every direction at once. The DB-1000 of August 1984 recognized characters written on the glass with a fingertip. The CFX-200 and CFX-400 were scientific calculator watches, with logarithms and trigonometry on the wrist. The TC500 of 1983 had touch-sensitive keys printed on the crystal. A mail-order advertisement in Popular Science in July 1986 offered the “Memo-Plan” Data Bank calculator watch, storing “50 sets of 5 letters and 12 numbers”, at $39.95 in black plastic as the DBC-60, $49.95 in chrome and steel as the DBC-600 and $69.95 gold-toned, and the “26 function scientific” at $49.95 as the CFX-40 or $59.95 as the chrome-plated CFX-400: a calculator watch now cost what a cheap pocket calculator did.

Figure 2 — The Casio CFX-400 scientific calculator watch of the mid-1980s, with sine, cosine, logarithms and base conversions on its keys.
Figure 2 — The Casio CFX-400 scientific calculator watch of the mid-1980s, with sine, cosine, logarithms and base conversions on its keys. — Photo: Septagram, Wikimedia Commons, public domain.
Figure 3 — "New! From Casio": a mail-order advertisement in Popular Science, July 1986, offering the Memo-Plan Data Bank (DBC-60, DBC-600, DBC-600G) from $39.95 and the 26-function scientific (CFX-40, CFX-400…
Figure 3 — "New! From Casio": a mail-order advertisement in Popular Science, July 1986, offering the Memo-Plan Data Bank (DBC-60, DBC-600, DBC-600G) from $39.95 and the 26-function scientific (CFX-40, CFX-400) from $49.95. — Image: Popular Science, July 1986, via Wikimedia Commons, public domain.
Figure 4 — The Casio TC500 "Touch Sensor Cal" of 1983: the keys are printed on the glass over the display.
Figure 4 — The Casio TC500 "Touch Sensor Cal" of 1983: the keys are printed on the glass over the display. — Photo: Binarysequence, Wikimedia Commons, CC BY-SA 4.0.

3.2 The DBC line

The Data Banks with a calculator, the DBC series, run from the 1980s to my DBC-32. A collector posting as lookatwrist on the WatchUSeek forum has pieced the line together from his own watches and their case backs; the dates are his, but the module numbers can be checked against the backs.

Table 1 — The DBC line

YearModelsModuleRecordsWhat was new
1985DBC-60, DBC-60056350a password-protected “secret” area
1988DBX-100261100a full dot-matrix display
1989DBC-61, DBC-61067650countdown timer, world time
1991DBC-62676separate rubber keys instead of a membrane
1994–95DBM-150, DBM-1511079150Memory Protect: records survive a battery change
1995DBC-63 (Telememo 50)127650Illuminator electroluminescent backlight
1995DBC-30 (Telememo 30)125330five alarms
1996DBC-80, -81, -150, -3101476–148680–300Telememo 80, 150 and 300
1999DBC-V501591voice memo
2001DBC-W1502296Waveceptor radio-set time
2004–08DBC-32 family288825multi-lingual, LED auto light
2011DBC-611322825the 2888’s features in a 1980s-style case
Figure 5 — The Casio DBX-100 of 1988, with its dot-matrix display and 100 records.
Figure 5 — The Casio DBX-100 of 1988, with its dot-matrix display and 100 records. — Photo: Stollenbaeck, Wikimedia Commons, CC BY-SA 4.0.
Figure 6 — The DBC-810 Telememo 80 of 1996, with the Illuminator backlight and "Memory Protect" printed on the case.
Figure 6 — The DBC-810 Telememo 80 of 1996, with the Illuminator backlight and "Memory Protect" printed on the case. — Photo: U1Quattro, Wikimedia Commons, CC BY 3.0.

Two of those changes matter for anyone who owns one. Before Memory Protect, which arrived with the DBM-150, a Data Bank kept its records in memory that needed power; the earlier models carried two cells, so that changing one at a time kept the records alive. The DBM and the “Memory Protect” models that followed stored them in EEPROM, which keeps its contents without power. And the Illuminator of 1995 lit the display with an electroluminescent panel, before LEDs took over in later modules, mine among them.

Casio also made Data Banks that dialled. The DBA watches played the touch tones of a stored number into a telephone handset; Wikipedia calls the DBA-800 “the world’s first phone dialler watch”.

Figure 7 — The Casio DBA-800 Data Bank, which could dial a stored number by sounding its touch tones into a telephone.
Figure 7 — The Casio DBA-800 Data Bank, which could dial a stored number by sounding its touch tones into a telephone. — Photo: U1Quattro, Wikimedia Commons, CC BY 3.0.
Figure 8 — A Casio CA-502 alarm chronograph calculator watch of 1984.
Figure 8 — A Casio CA-502 alarm chronograph calculator watch of 1984. — Photo: orion, Wikimedia Commons, CC BY-SA 2.0.

3.3 Back to the Future

In 1988 Casio introduced the CA-53W, a small, light calculator watch that is still on sale. It is the most famous calculator watch of all, because of a film. In Back to the Future (1985) Marty McFly, played by Michael J. Fox, wears a Casio calculator watch; since the CA-53W did not yet exist, it was its predecessor, the CA-50. In Part II (1989) and Part III (1990) he wears the CA-53W. Many accounts give the CA-53W for the first film too, which its 1988 introduction rules out. The CA-53W turned up again on Walter White’s wrist in Breaking Bad, and for the first film’s fortieth anniversary, on 27 October 2025, Casio issued a tribute model, the CA-500WEBF-1A, at $120.

Figure 9 — The Casio CA-50 (left) and the CA-53W-1EZ, the two calculator watches Marty McFly wore in the Back to the Future films.
Figure 9 — The Casio CA-50 (left) and the CA-53W-1EZ, the two calculator watches Marty McFly wore in the Back to the Future films. — Photo: VSchagow, Wikimedia Commons, CC BY-SA 4.0.

3.4 Wrist computers

Seiko took the opposite course from Casio and tried to make the watch a computer. The Data 2000 of 1983 came with a pocket keyboard that transferred notes to the watch by magnetic coupling; it sold for $295. The UC-2000 “Wrist Information System” of 1984, which Seiko calls “the world’s first wristwatch with computer functions”, docked onto a keyboard unit, the UC-2100, and onto a terminal with a printer and Microsoft BASIC, the UC-2200; the watch held 2,000 characters. The RC-1000 “Wrist Terminal” of the same year had no keyboard at all and loaded its data from a personal computer through a serial cable; a British review priced it at £119.

Figure 10 — The Seiko Data 2000 of 1983 in its box, with the pocket keyboard that loaded notes into the watch.
Figure 10 — The Seiko Data 2000 of 1983 in its box, with the pocket keyboard that loaded notes into the watch. — Photo: Joe Haupt, Wikimedia Commons, CC BY-SA 2.0.

A decade later, Timex and Microsoft made the idea simple. Bill Gates demonstrated the Timex Data Link on 21 June 1994: the watch read appointments and telephone numbers from flashing bars on a computer’s screen, through an optical sensor in its face, without a cable at all. It cost about $130 in 1996, and NASA qualified it for space flight. Casio’s data watches of the time, by one 1995 review, sold for a third to a half of its price.

Figure 11 — A Timex Data Link 150, which loaded its data optically from flashing bars on a computer screen.
Figure 11 — A Timex Data Link 150, which loaded its data optically from flashing bars on a computer screen. — Photo: Dr.K., Wikimedia Commons, CC BY-SA 3.0.
Figure 12 — Commander Sidney Gutierrez aboard the Space Shuttle Endeavour on mission STS-59, 14 April 1994, wearing a Casio Data Bank watch.
Figure 12 — Commander Sidney Gutierrez aboard the Space Shuttle Endeavour on mission STS-59, 14 April 1994, wearing a Casio Data Bank watch. — Photo: NASA, Wikimedia Commons, no known copyright restrictions.

3.5 Decline and revival

The calculator watch’s fortunes followed the gadgets that replaced it. Wikipedia dates its fading to the mid-1990s, as cheap mobile telephones and personal digital assistants spread; lookatwrist puts the peak of the Data Bank in 1996, the year of the Telememo 300. Once every telephone number lived in a telephone, twenty-five on a wrist had little point, and the Data Banks shrank back from hundreds of records to the 25 of my DBC-32.

What kept the line alive was affection. In 2018 Casio founded its VINTAGE sub-brand around its 1970s-to-1990s designs; the CA-53W, the A168 and the Data Banks sell new as retro classics, and the smartwatch, which does everything a Data Bank did and much more, has made the calculator watch a deliberate choice rather than a necessity. Enthusiasts have even built their own: the μWatch is an open-source scientific calculator watch designed for the electronics hobbyist to build.

Figure 13 — The μWatch, an open-source, home-built scientific calculator watch: the calculator watch as a hobbyist's project.
Figure 13 — The μWatch, an open-source, home-built scientific calculator watch: the calculator watch as a hobbyist's project. — Photo: Binarysequence, Wikimedia Commons, CC BY-SA 3.0.

Sources

  • Casio corporate history, chapter 2 (CD-40, sales); Casio company history, 1980s and 1990s; Casio heritage pages, 1980s; Casio Germany on the VINTAGE brand.
  • lookatwrist, “History of Casio DBC, DBX, and DBM Data Bank Calculator Watches”, WatchUSeek, 11 August 2020.
  • Popular Science, July 1986, p. 78 (advertisement, via Wikimedia Commons).
  • Wikipedia, “Casio Databank”, “Casio CA-53W”, “Calculator watch” and “Timex Datalink”; G-Central on the CA-53W and the CA-500WEBF; Pocket Calculator Show, “Nerd Watch Museum” (2002).
  • Seiko, “100 Stories: Innovation”; raredigitalwatches.com on the Seiko Data 2000, UC-2000 and RC-1000; Gizmodo, “The gadget we miss: the calculator watch” (2013).
  • Casio, Operation Guide 3228 (MO1106-EA, 2011), for the DBC-611.

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