From the 264 concept to Plus/4
The Smithsonian records that the machine was announced as the configurable Commodore 264 concept in January 1984 and became the factory-configured Plus/4 after that ROM-selection plan was dropped. This history supports a family-level page without treating the Plus/4 as a reduced C64. [1]
7501 and TED
The service manual identifies the 7501 as an HMOS 6510 derivative operating at 0.89 or 1.76 MHz. TED handles video processing and supports documented 40-by-25 text, 320-by-200 graphics, 16 colors at eight luminance levels, and either two tone generators or one tone generator plus white noise. [2]
Memory, BASIC 3.5, and built-in applications
The published configuration combines 64 KB RAM and 64 KB ROM, with 60 KB RAM accessible for BASIC. BASIC 3.5 and a machine-language monitor form a distinct development environment. The four integrated application categories—word processing, spreadsheet, file management, and graphics—could exchange information according to the integrated-software manual. [2] [3]
Connections and preservation trail
Service documentation lists serial, cassette, cartridge/parallel-disk, two joystick, user/modem, RF, video, and audio connections, and names the C1551 fast disk drive as an intended peripheral. Smithsonian collection records preserve both the computer and its user-manual context. [2] [4]