Compaq Portable
The Compaq Portable is an early portable computer which was one of the first IBM PC–compatible systems. It was Compaq Computer Corporation's first product, to be followed by others in the Compaq Portable series and later Deskpro series. It is not simply an 8088-CPU computer that runs a Microsoft DOS as a PC "work-alike", but contains a reverse-engineered BIOS and Compaq DOS compatible with IBM's PC DOS. The computer is also an early variation on the idea of an "all-in-one".
The Compaq Portable was announced in November 1982 and first shipped in March 1983. It became available two years after the similar, but CP/M-based, Osborne 1 and Kaypro II. Columbia Data Products' MPC 1600 "Multi Personal Computer", the first IBM PC compatible system, had come out in June 1982.
Production and sales
The Compaq Portable was announced in November 1982 and first shipped in March 1983, priced at with a single half-height " diskette drive or US$3,590 for dual, full-height diskette drives. The Compaq Portable folds up into a luggable case the size of a portable sewing machine.IBM responded to the Compaq Portable with the IBM Portable PC, developed because its sales force needed a comparable computer to sell against Compaq.
Compaq sold 53,000 units in the first year with a total of in revenue, an American Business record. In the second year revenue hit setting an industry record. Third year revenue was at, another US business record.
Design
The Compaq Portable has basically the same hardware as an IBM PC, with Compaq's BIOS instead of IBM's, transplanted into a luggable case specifically designed to fit as carry-on luggage on an airplane. All Portables shipped with 128KB of RAM and 1-2 double-sided double-density 360 KB disk drives. Like the non-portable IBM PC, the Compaq Portable runs on power from an AC outlet only; it has no battery.The machine has a hybrid of the IBM MDA and CGA which supports the latter's graphics modes, but uses the former's high-quality character set in 80x25 text mode. When using the internal monochrome monitor the 9×14 font is used, and the 8×8 one when an external monitor is used. With a larger external monitor, the graphics hardware is also used in the original Compaq Deskpro desktop computer.
Compaq used a "foam and foil" keyboard from Keytronics. The foam pads the keyboards use to make contact with the circuit board when pressed disintegrate over time, due to both the wear of normal use and natural wear. The CRT display also suffers from a low refresh rate and heavy ghosting.
Software
Compaq's efforts were possible because IBM had used mostly off-the-shelf parts for the PC and published full technical documentation for it, and because Microsoft had kept the right to license MS-DOS to other computer manufacturers. The only difficulty was the BIOS, because it contained IBM's copyrighted code. Compaq solved this problem by producing a clean room workalike that performs all documented functions of the IBM PC BIOS, but was completely written from scratch.Although numerous other companies soon also began selling PC compatibles, few matched Compaq's achievement of essentially-complete software compatibility with the IBM PC until Phoenix Technologies and others began selling similarly reverse-engineered BIOSs on the open market.
Compaq shipped the Portable with Compaq DOS, its own version of MS-DOS. The first Portables use version 1.10, essentially identical to PC DOS 1.10 except for having a standalone BASIC that did not require the IBM PC's ROM Cassette BASIC, but this was superseded in a few months by DOS 2.00 which added hard disk support and other advanced features.
Aside from using DOS 1.x, the initial Portables are similar to the 16 KB – 64 KB models of the IBM PC in that the BIOS was limited to 544 KB of RAM and did not support expansion ROMs, thus making them unable to use EGA/VGA cards, hard disks, or similar hardware. After DOS 2.x and the IBM XT came out, Compaq upgraded the BIOS. Although the Portable was not offered with a factory hard disk, users commonly installed them. Starting in 1984, Compaq began offering a hard disk-equipped version, the Portable Plus, which also featured a single half-height floppy drive. The hard disk offered would be 10 to 21 megabytes, although bad sectors often reduced the space available for use.
In 1985, Compaq introduced the Portable 286, but it was replaced by the more compact Portable II in a redesigned case within a few months. The Portable 286 featured a full-height hard disk, and the options of one half-height floppy drive, two half-height floppy drives, or a half-height floppy drive and a tape backup drive.
Competitors
Other IBM PC "work-alikes" included the MS-DOS and 8088-based, but not entirely IBM PC software compatible, Dynalogic Hyperion, Eagle Computer's Eagle 1600 series, including the Eagle Spirit portable, and the Corona personal computer. The latter two companies were threatened by IBM for BIOS copyright infringement, and settled out of court, agreeing to re-implement their BIOS.There was also the Seequa Chameleon, which had both 8088 and Z80 CPUs to alternately run MS-DOS or CP/M. Unlike Compaq, many of these companies had previously released computers based on Zilog's Z80 and Digital Research's CP/M operating system. Like Compaq, they recognized the replicability of the IBM PC's off-the-shelf parts, and saw that Microsoft retained the right to license MS-DOS to other companies. Only Compaq was able to fully capitalize on this, by aiming for complete IBM PC and PC DOS software compatibility, while reverse-engineering the BIOS to head off copyright legal claims.
Other contemporary systems include the portable Commodore SX-64, also known as the Executive 64, or VIP-64 in Europe, a briefcase/suitcase-size "luggable" version of the popular Commodore 64 home computer built with an 8-bit MOS 6510 CPU microprocessor, and the first full-color portable computer. Like the Z80 and "work-alike" portables, its sales fell into insignificance in the face of the Compaq Portable series.