modem card and could emulate a Model III. The Model 4D with bundled Deskmate productivity suite was introduced in early 1985. It has a revised CPU board using faster gate array logic which includes the floppy controller and RS-232C circuitry, all on a single board. The computer has two internal double-sided diskette drives, and is the last model descended from the 1977 Model I. It retailed for at its introduction in 1985. During 1987–1988 the retail stores removed the Model 4Ds from display but they were available by special order through 1991. See also List of TRS-80 games List of TRS-80 software List of TRS-80 clones SoftSide, magazine with BASIC programs for the TRS-80 and other microcomputers The Alternate Source Programmer's Journal, TRS-80 magazine with technical programming articles Notes References Further reading External links Radio Shack Catalog Archive (1939–2011) Radio Shack Model I and II catalog RSC-3 trs-80.com : Ira Goldklang's TRS-80 Revived Site TRS-80 Model 1 at www.old-computers.com REM 80 – The North West TRS-80 USers Group Magazines TRS-80 Emulator in Javascript : online emulation of Model III BASIC & commercial arcade games jTandy, another javascript TRS-80 emulator : online emulation of Model III BASIC & commercial arcade games Tandy Model 4/4P Technical Reference LDOS 5.1 User Manual Byte magazine review of LDOS 5.1 Z80-based home computers Home computers Computer-related introductions in 1977 Products introduced in 1977 8-bit computers Early microcomputers Products and services discontinued in 1981