Compaq is now the low-end brand name used by H-P, but Compaq Computer Corporation has in important place in PC history. Compaq was founded in 1982 by three men from Texas Instruments who invested $1,000 each to form their own company. Sketched on a paper place mat in a Houston pie shop, the first product was a "compact" portable personal computer.
The Compaq Portable was the first 100% compatible IBM computer clone. It could run the software written for IBM’s PCs, which was a major achievement at the time. Compaq couldn't just copy IBM's BIOS (Basic Input/Output System, the internal software that determines what a computer can do), to make their new machine guaranteed IBM compatible. It would be illegal, and easily proven by IBM. Compaq determined to reverse-engineer IBM's BIOS, and used two sets of programmers, one group who had access to IBM's source code and another that knew nothing about it.
The first group analyzed the original code, and made notes of exactly what it did. The second group analyzed the notes, and wrote their own BIOS that performed identically. It took one year and a million dollars to accomplish.
More than a mere IBM clone, the Compaq Portable was something different, it was transportable, designed so it can easily be taken aboard an airliner as carry-on luggage. The machine was very successful for Compaq and the company took in $111 million in its first year, a record in American business.
This precursor of today’s lightweight laptops and palmtops, weighed 28 pounds, had a 9-inch monochrome display, and cost $3590 with two 5-1/4” floppy drives and 640K of RAM. A basic version with just one drive and 128K of RAM, sold for $2995, considered a bargain compared to IBM prices at the time. (info from OldComputers.net and Byte magazine)