Casio Tri-Graph TGW-10 – c. 1988 - Module 827 – rare late 1980s digital analog simulation – overhauled, new strap

The Tri-Graph is one of the most idiosyncratic ideas Casio pursued during the high point of the digital watch era: three circular graphic fields in the upper third of the dial simulate analog hands entirely digitally. It is the rarest watch in this acquisition and is consistently listed on the international collector's market as hard to come by.

The case back is stamped with CASIO, the module number 827 in a box, the model designation TGW-10, as well as the inscriptions STAINLESS STEEL BACK, WATER RESISTANT, and JAPAN T. The dial is marked with CASIO, TRI GRAPH, and 10 BAR.

When the digital watch imitated the analog watch

At the beginning of the eighties, the matter seemed decided: the digital display was more accurate, cheaper, and feature-rich, while the analog watch was a dying breed. The only problem was that time could not be read as quickly on a digit field as it could on a watch face – a hand shows not just the time, but also how much is left.

Casio's answer was the Tri-Graph. Instead of returning to mechanics, they recreated the watch face in the LCD: on the left, the hour runs as a hand graphic; on the right, the second as a rotating segment; and in the center sits the day-night indicator. It is an attempt to combine the advantages of both display types in one screen – and a historical document from the brief moment when the digital watch concerned itself with what it had just supplanted.

Design

A robust black resin case with distinct protective bars around the pushers, similar to those Casio developed in parallel for its sports watch lines. The four-screw steel back and the 10 BAR rating underscore its structural seriousness.

On the dial, three levels are layered: at the top, the three graphic fields with labels for SIG ON, ALM ON, as well as TIME, AM, PM, and SEC; in the middle, the large seven-segment field for time and date; and to the left of that, the function bar with ALM, DUAL, TMR, and ST.W. Below this, the lettering TRI GRAPH appears between two blue decorative lines.

In addition to the time display, the watch offers an alarm, second time zone, timer, and stopwatch function.

Dating

The module number 827 points to the end of the 1980s; on the collector's market, the reference is predominantly dated to 1988. A day-accurate dating is not possible for Casio modules of this series without factory documentation; we provide this as an indication, not as a confirmed date.

Condition and provenance

The watch comes from Japan, where it was opened, inspected, and cleaned by a watchmaker, and fitted with a new battery. All three graphic fields and all functions work.

This is a pre-owned original with signs of wear. All display elements are triggered correctly, and the graphic fields are complete. The main display has a warm, amber-colored hue – a sign of aging in the polarizing film, which regularly occurs in modules of this generation and does not impair readability. The plastic crystal shows fine scratches and slight haziness in the upper area. The resin case is free of cracks, and the pushers are complete and functional. The steel back shows fine signs of wear, all four screws are present, and the engraving is fully legible. The polyurethane strap is new.

The actual condition is shown unretouched in the product photos.

Technical Specifications

• Brand: Casio
• Model: TGW-10
• Module: 827
• Movement: Quartz, digital (LCD), battery-powered
• Functions: Time, second, date, three graphic displays, alarm, second time zone, timer, stopwatch
• Case: Resin with screwed stainless steel back
• Diameter without crown: approx. 40 mm
• Height: 10.8 mm
• Lug-to-lug: 42.1 mm
• Lug width: 14 mm
• Weight incl. strap: 27 g
• Dial: black with three circular graphic fields
• Strap: new polyurethane strap
• Dating: c. 1988
• Provenance: Japan

For whom?

For collectors of digital Casio models beyond the reissued classics. For everyone interested in the historical moment when the digital watch began to imitate the analog watch instead of replacing it. And for buyers who know how rarely this reference is offered in functional condition.

Warranty (used)

This is a used item. The limitation period for claims for defects under statutory warranty is 12 months from delivery.

Note on water resistance

Water resistance is not guaranteed. The 10 BAR rating refers to the condition at the time of delivery. To protect the movement, the watch should not come into contact with water or moisture.