IBM 5150

IBM 5150/IBM PC
The IBM PC
Manufacturer:	IBM
Year Introduced:	1981
Word Size:	16 bit

The IBM 5150 was IBM's entry into the personal computer marketplace, the IBM PC. It was introduced in stores on 1981-08-12. The original configuration had a motherboard designed for up to 64KB of RAM, and a cassette tape drive, but could be expanded to include a diskette drive, and a hard disk. At the beginning they were advertised for around $1,600 for a unit with just 16KB of RAM and a keyboard[1]. Retail would be around $1,000 though[2], or maybe more likely in the $1,300 - $1,400 range[3]).

In practice you would add a at least a video adapter, probably some RAM, and a floppy disk drive. Then the price would be quite different. Back then, both types of disk drives were of the 5 1/4" full height form factor. IBM made the PC an open standard, publishing not only schematics, but also including a BIOS listing in the technical reference. When people wished to build clones of the IBM PC, IBM would license them for a 5% royalty fee, which not only made the PC a popular platform to clone, but also with the available schematics, allowed for everyone to be pin compatible with the ISA slots, creating a thriving hardware expansion business.

The IBM PC included Microsoft BASIC in ROM, which allowed the PC to function like many of the computers of the time with a simple ROM BASIC. With the addition of a disk drive, OS options included CP/M and MS-DOS at the time of sale.

The IBM PC, also established the 8 bit expansion slot, or ISA bus standard as it was later called.

IBM PC Motherboard

The PC was replaced by the wildly popular IBM XT.