Compaq Portable Plus
| Industry | Computer hardware |
|---|---|
| Founded | November 1982 |
| Headquarters | Houston , United States |
Key people | Rod Canion (co-founder) |
| Products | Compaq Portable series, personal computers |
| Website | www |
The Compaq Portable was among the earliest IBM PC compatible machines, marking Compaq Computer Corporation's debut in the personal computer arena. Unlike many initial PC clones, it employed a BIOS created through reverse engineering and utilized an MS-DOS variant closely matching IBM's PC DOS. This approach ensured extensive compatibility with IBM PC software, establishing Compaq as a trailblazer in portable computing and reinforcing its reputation for authentic IBM PC compatibility.
Introduced in March 1983 with a price tag of $2,995, the Compaq Portable followed earlier portable machines such as the CP/M-based Osborne 1 and Kaypro II, along with Columbia Data Products' MPC 1600—the first IBM PC compatible system released in June 1982. Other contemporaneous devices included Dynalogic's Hyperion, Eagle Computer's Eagle 1600 series, and Corona Data Systems' PCs. Many of these competitors encountered legal disputes concerning BIOS copyright violations and were compelled to redesign their BIOS implementations.
In contrast to these companies, Compaq successfully duplicated IBM’s BIOS through reverse engineering without infringing on copyrights, thereby avoiding litigation while guaranteeing full software compatibility. This method set Compaq apart in an industry that had largely concentrated on Z80 and CP/M platforms but was beginning to recognize the lucrative prospects of MS-DOS licensing.
Additional portable systems from that period, such as the Commodore SX-64—a color portable iteration of the Commodore 64—were unable to compete effectively with the Compaq Portable lineup, which dominated due to its genuine IBM PC compatibility and extensive software support.
Production and sales
Announced in November 1982 and shipped by March 1983, the Compaq Portable was priced at , featuring either a single half-height " diskette drive or dual full-height drives for US$3,590. Weighing , it folded into a carry case roughly the size of a portable sewing machine.
To counter Compaq’s product, IBM introduced the IBM Portable PC.
In its inaugural year, Compaq sold 53,000 units, generating in revenue—a record for American business at that time. Revenue climbed to in the second year and further increased to in the third year, both figures setting new industry benchmarks.
Design
The hardware of the Compaq Portable closely mirrored that of the IBM PC but incorporated Compaq’s own BIOS within a chassis designed for portability akin to carry-on luggage. Each unit came equipped with 128 KB of RAM and one or two double-sided 360 KB floppy drives. The system operated exclusively on AC power without any battery option.
Its video subsystem merged IBM MDA’s high-quality 80x25 text mode character set with CGA graphics capabilities. This hybrid configuration impressed industry leaders such as Mitch Kapor during Lotus 1-2-3 presentations. Users could toggle between the internal monochrome display (rendering text with a 9×14 font) and an external monitor (using an 8×8 font) via a keyboard shortcut. The graphics hardware also supported larger external monitors commonly used with Compaq’s Deskpro desktop models.
The keyboard employed "foam and foil" contact pads supplied by Keytronics—a technology prevalent in several systems of that era but known to degrade over time. Additionally, the CRT display suffered from low refresh rates which caused visible ghosting effects.
Software
Compaq's achievement was largely due to IBM's strategy of utilizing standard components and openly available technical specifications, alongside Microsoft's approach of licensing MS-DOS to various hardware manufacturers. The primary obstacle was the BIOS, which contained proprietary IBM code protected by copyright. Compaq successfully navigated this by creating a clean room BIOS replica that duplicated all IBM PC BIOS functionalities without directly copying any code.
Although numerous companies produced IBM PC-compatible machines, only a handful achieved software compatibility close to that of Compaq’s systems until Phoenix Technologies and others began offering commercially available reverse-engineered BIOS solutions.
The initial Portables were shipped with Compaq DOS 1.10, closely mirroring PC DOS 1.10 but featuring a standalone BASIC interpreter; this was later superseded by DOS 2.00, which introduced support for hard drives and additional advanced capabilities.
Early versions of the Portable resembled the IBM PC in design, with memory limits ranging from 16 KB to 64 KB and BIOS constraints that prevented the use of EGA/VGA graphics cards or hard disk drives. Following the release of DOS 2.x and the IBM XT, Compaq enhanced the BIOS. Although these early models did not come with factory-installed hard disks, users frequently added them themselves. Starting in 1984, Compaq launched the Portable Plus, which included a hard disk ranging between 10 and 21 MB and a half-height floppy disk drive.
In 1985, Compaq released the Portable 286, featuring a full-height hard drive and several floppy drive configurations; this model was soon succeeded by the more compact Portable II housed in a redesigned enclosure.
Reception
BYTE commended the Compaq Portable for its portability, affordability, and extensive compatibility with IBM PC software after evaluating various applications including IBM PC DOS and CP/M-86. InfoWorld described it as "an excellent, convenient machine designed and priced for professional use." PC Magazine emphasized its robust construction, crisp display quality, and comprehensive software compatibility, recommending it as an alternative for running IBM PC software without owning an IBM PC.
Compaq Portable Plus
Introduced in 1983, the Compaq Portable Plus improved upon the original by replacing one floppy disk drive with a hard drive and incorporating gold-toned logos and badges. This enhancement addressed a market need previously served only by third-party computer retailers, thereby creating a direct revenue stream for Compaq.
Compaq Portable 286
The Compaq Portable 286, modeled after the PC AT, retained the original Portable’s chassis but upgraded to a 6/8 MHz 286 processor along with a faster 20 MB hard drive, delivering enhanced performance tailored to business users.
Compaq Portable series
The initial Compaq Portable gave rise to a product line that included the smaller and lighter Compaq Portable II, which was more cost-effective but offered fewer upgrade possibilities and featured a slower hard drive. Later models—such as the Compaq Portable III, Compaq Portable 386, Compaq Portable 486, and Compaq Portable 486c—continued to advance the series by incorporating improved features designed for professional environments.