1982: Compaq Portable - The First IBM Compatible
Compaq Computer was formed in 1982 and their first product announced in November 1982 was the Compaq Portable. The company even derived its name from the "compact" nature of this machine. But at 28 pounds and the size of a sewing machine, it can presently be considered compact only in comparison to its main competitor in 1982, the IBM-PC. The Compaq was a competitor to the IBM-PC because it ran the same operating system and claimed 100% compatibility with software written for the IBM-PC. Compaq had to create their BIOS code from scratch to avoid a copyright infringement suit from IBM. The Compaq Portable superceded the Osborne 1 which could not run PC-DOS and had a smaller screen.
The Compaq Portable was similar in performance to the IBM-PC with a 4.77 MHz 8088 processor, 128k of RAM, a single full-height 320k 5-1/4" floppy disk, and a built-in 9-inch green monochrome monitor. The complete system sold for $3000.