The original PS/1, based on a 10 MHz Intel 80286 CPU, was designed to be easy to set up and use. Like many Tandy 1000 models, it had DOS 4.01 built in to ROM, but it made the unusual decision to put the power supply for the entire unit in the monitor, making use of third-party monitors impossible and limiting the usefulness of the computer if the monitor needed service (similar to the problems of the Coleco Adam years earlier). It featured 1 MB of memory and a 30 MB hard disk.
The first PS/1 models suffered from very limited expansion capabilities, but later models were standard PCs with all the standard ports, ISA expansion slots, operating system stored on disk rather than in ROM, and, in many cases, even standard LPX-architecture motherboards—at the expense of being no easier to set up than any other run-of-the-mill PC.
Like the PCjr, the PS/1's name suggested a more limited machine than IBM's business line. However, the PS/1 had a higher degree of compatibility with IBM's business computers. Ironically, many PS/1s shipped from the factory with MS-DOS and Microsoft Windows, rather than IBM's PC DOS and/or OS/2. The PS/1 line was sold in consumer electronics stores alongside offerings from Compaq, Hewlett-Packard, Packard Bell, and others.
The PS/1 line was discontinued in 1994 and replaced with the Aptiva line, which was architecturally very similar to the PS/1 but had a more marketing-friendly name. Aptivas were sold in the United States until early 2000, when price pressures made the line unprofitable and IBM withdrew from the retail market entirely.