Compaq Portable
| Company type | Public |
|---|---|
| Industry | Computer hardware |
| Founded | February 1, 1982 |
| Founder | Rod Canion, Jim Harris, Bill Murto |
| Headquarters | Houston, Texas , United States |
| Products | Compaq Portable, Compaq Deskpro, Compaq Portable Plus, Compaq Portable 286, Compaq Portable II |
| Website | www |
The Compaq Portable stands as one of the earliest portable computer models and among the first to offer full IBM PC compatible functionality. This device marked the debut product of Compaq Computer Corporation, initiating both the Compaq Portable series and subsequently the Compaq Deskpro lineup. Distinct from many competitors, it incorporated a completely reverse-engineered BIOS alongside an MS-DOS variant closely mirroring IBM's PC DOS, which ensured extensive compatibility with software designed for the IBM PC. Its construction represented an early form of an "all-in-one" system.
Launching two years after CP/M-based portable machines such as the Osborne 1 and Kaypro II, the Compaq Portable followed in the footsteps of the IBM PC compatible Columbia Data Products MPC 1600 introduced in mid-1982. Other contemporaneous MS-DOS and 8088-based "clones" included Dynalogic's Hyperion, Eagle Computer's Eagle 1600 series (with the portable Eagle Spirit), and Corona Data Systems' personal computers. Notably, Eagle and Corona resolved legal challenges from IBM over BIOS copyrights by redeveloping their BIOS software. The Seequa Chameleon featured dual processors (8088 and Z80) enabling operation under MS-DOS or CP/M but did not achieve complete IBM PC compatibility.
While many rivals originated from Z80/CP/M platforms, Compaq leveraged the IBM PC’s modular design and Microsoft's licensing of MS-DOS to accomplish full IBM PC compatibility through BIOS reverse engineering, thereby circumventing legal complications.
Among other options at the time was the Commodore SX-64, a portable briefcase-sized version of the Commodore 64 equipped with an 8-bit MOS 6510 CPU and a full-color display. Despite this, such systems struggled to capture significant market share compared to the IBM-compatible Compaq Portable series.
Production and sales
Announced in November 1982 and released in March 1983, the Compaq Portable was initially priced at , featuring a single half-height " diskette drive or US$3,590 for models with dual full-height drives. Weighing , it folded into a compact case roughly equivalent in size to a portable sewing machine.
In response, IBM introduced the IBM Portable PC to equip its sales team with a comparable offering against Compaq’s product.
During its first year on the market, Compaq sold 53,000 units, generating revenue—an unprecedented achievement for an American business at that time. Sales revenue increased to in the second year and further rose to in the third year, setting consecutive records within the industry.
Design
The hardware inside the Compaq Portable closely mirrored that of the IBM PC but utilized Compaq’s proprietary BIOS. It was encased within a portable chassis sized to meet airline carry-on luggage requirements. All units were equipped with 128 KB of RAM and one or two double-sided double-density 360 KB floppy disk drives. The system operated exclusively on AC power without any battery option.
Its video subsystem combined features from IBM MDA’s high-quality 80x25 text mode character set with CGA’s graphical capabilities. Users could toggle between an internal monochrome display (rendering text with a 9×14 font) and an external monitor (using an 8×8 font) through a specific key command. The graphics hardware also supported larger external monitors similar to those paired with Compaq Deskpro desktop computers.
The keyboard employed foam-and-foil contact pads manufactured by Keytronics, akin to those used in other prominent keyboards of that period. However, these pads were prone to degradation over time due to wear. Additionally, the CRT screen suffered from a low refresh rate and noticeable ghosting effects.
Software
Compaq's achievement was largely due to IBM's reliance on standard components and openly available technical specifications, combined with Microsoft's strategy of licensing MS-DOS to various hardware producers. The critical obstacle was the BIOS, which contained IBM's proprietary code; Compaq successfully navigated this by developing a clean room BIOS clone that duplicated IBM PC functionality without directly copying any code.
Although numerous manufacturers created PC-compatible machines, only a handful approached Compaq's level of comprehensive software compatibility with the IBM PC until companies like Phoenix Technologies began offering commercially reverse-engineered BIOS versions.
The initial Portables came pre-installed with Compaq DOS 1.10, which was essentially the same as PC DOS 1.10 but included a standalone BASIC interpreter independent of the IBM PC's ROM Cassette BASIC. This version was soon superseded by DOS 2.00, which introduced support for hard disks and additional advanced capabilities.
Early Portable models shared similarities with IBM PC designs but featured a limited BIOS memory capacity (544 KB) and lacked support for expansion ROMs, thereby restricting compatibility with EGA/VGA graphics cards and hard drives. Following the release of DOS 2.x and the IBM XT, Compaq enhanced the BIOS. While initial units did not come equipped with hard drives, many users installed them independently. Starting in 1984, Compaq offered the Portable Plus model, which included a hard disk ranging from 10 to 21 MB alongside a half-height floppy drive.
In 1985, Compaq launched the Portable 286, which was shortly succeeded by the more compact Portable II. The Portable 286 featured a full-height hard disk and offered configuration options such as one or two half-height floppy drives or a tape backup drive.
Reception
BYTE commended the Compaq Portable prototype for its portability, cost-effectiveness, and strong IBM PC compatibility, verifying that most tested applications operated successfully. InfoWorld described it as "an excellent, convenient machine designed and priced for professional use." PC Magazine emphasized its durable construction, sharp display quality, and flawless software compatibility, recommending it for users who required IBM PC software without purchasing an IBM PC.
Compaq Portable Plus
Introduced in 1983, the Compaq Portable Plus enhanced the original by replacing one floppy disk drive with a hard drive and featuring gold-background logos and badges. This officially incorporated modifications previously performed by third-party vendors, establishing an additional revenue stream for Compaq.
Compaq Portable 286
The Compaq Portable 286 represented Compaq’s adaptation of the PC AT, utilizing the original Portable chassis and outfitted with a 6/8 MHz 286 processor along with a high-speed 20 MB hard drive, aimed at business users requiring improved performance.
Compaq Portable series
The initial Compaq Portable gave rise to a line of successive models. The Compaq Portable II was a smaller, lighter, and more cost-effective iteration of the Portable 286 but offered fewer upgrade possibilities and employed a slower hard drive. Later versions included the Compaq Portable III, Compaq Portable 386, Compaq Portable 486, and the Compaq Portable 486c, each delivering enhanced performance and features to satisfy changing market requirements.