IBM 1390305 Model M Terminal Keyboard 5-Pin DIN AT Clicky Buckling Spring

IBM 1390305 Model M Terminal Keyboard 5-Pin DIN AT Clicky Buckling Spring

The IBM 1390305 is a full-size mechanical keyboard built around IBM's legendary buckling spring switch mechanism, manufactured on April 15, 1986. It connects via a coiled cable terminating in a 5-pin DIN (AT-style) plug and bears the Model M platform designation (PLT-NO J1), placing it among the earliest and most collectible examples of the Model M lineage. The buckling spring design produces the firm, tactile, audible feedback that made IBM keyboards the gold standard of their era and continues to make them sought after by collectors and enthusiasts today.

Specifications & What's Included

• Part Number: 1390305
• Platform / Variant: Model M (PLT-NO J1)
• EC Number: 528554
• Manufacture Date: 15 April 1986
• Switch Type: Buckling spring (mechanical)
• Connector: 5-pin DIN male (AT-compatible)
• Cable: Coiled, attached
• Layout: Full-size QWERTY
• Color: Beige / pearl white
• Includes: Keyboard with attached coiled cable only

Applications

The IBM Model M keyboard was originally designed for use with IBM PC/AT-class computers and IBM terminals in the mid-1980s. The 5-pin DIN connector is the standard AT keyboard interface used on IBM PC/AT and compatible systems from roughly 1984 through the early 1990s, before PS/2 mini-DIN and later USB superseded it. With a simple passive adapter (DIN-to-PS/2 or DIN-to-USB), Model M keyboards from this era can be connected to modern systems, which is a primary reason they remain in active use decades after production. This particular example dates from 1986, making it one of the earliest-production Model M units — a detail that appeals both to vintage computing enthusiasts restoring period-correct IBM systems and to mechanical keyboard collectors who prize early buckling spring examples for their construction quality and historical significance.