Final Firmware Version Released for Commodore Plus/4

The Commodore Plus/4 remains a significant yet often overlooked chapter in the history of 8-bit home computing, leading many enthusiasts to inquire about its specific hardware revisions. This article provides a definitive answer regarding the final firmware version released for the machine, detailing the ROM revision numbers that collectors and users should recognize. Readers will gain insight into the technical specifications of the final production run and understand how these revisions impact software compatibility and system stability today.

The Commodore Plus/4, part of the 264 series launched in 1984, utilized a split ROM architecture consisting of separate chips for the Kernal and BASIC interpreter. Unlike modern computers that receive software updates over time, the firmware for this system was burned into read-only memory chips at the factory. Throughout its production lifecycle, Commodore issued minor updates to address bugs and improve hardware compatibility. These updates are identified by revision numbers printed directly on the integrated circuits within the machine’s casing.

Historical records and hardware analysis by retro computing communities confirm that the final firmware version released for the Commodore Plus/4 is ROM Revision 3. This version is typically associated with part number 364960 for the USA market. Earlier units may contain Revision 1 or Revision 2 ROMs, which are known to have specific quirks regarding certain software titles and peripheral interactions. Revision 3 resolved many of these initial inconsistencies, providing the most stable environment for running commercial software and utilities designed for the platform.

For collectors and restorers, identifying this final version is crucial when authenticating late-production models or seeking the best experience for software preservation. While the differences between revisions are subtle to the average user, they represent the culmination of Commodore’s engineering efforts for the TED series before the line was discontinued. Consequently, ROM Revision 3 stands as the definitive final firmware state for the Commodore Plus/4.