type Laptop computer
country USA
year 1986
os IBM PC DOS
cpu Intel 8088
speed 4,77 MHz
ram 256 KB
disk dual 3,5″ 720 KB
graphic LCD CGA 640×200, 320×200
colors monochrome
ports parallel, serial, expansion
The IBM PC Convertible 5140 — IBM’s First True Laptop
Released in April 1986, the IBM PC Convertible (Model 5140) was IBM’s first genuine laptop computer — a battery-powered, clamshell-design machine that could be used away from a power socket and was compact enough for genuine portable use. At 5.5 kg, it was not light by modern standards, but it represented IBM’s first serious attempt at a portable computer that did not require a dedicated desk and power outlet. The Convertible used the same Intel 80C88 processor as the IBM PC but in a lower-power CMOS version, and ran for approximately two hours on its nickel-cadmium batteries.
The 3.5-inch Floppy Pioneer
The IBM PC Convertible was the first IBM machine to use 3.5-inch floppy disks — at the time an unusual format associated primarily with the Apple Macintosh (which had used them since 1984) and a few portable computers. IBM’s adoption of the 3.5-inch format was significant: when IBM endorsed a standard, the industry generally followed. The Convertible’s use of 3.5-inch floppies helped accelerate the format’s adoption across the PC industry, eventually making it the universal floppy standard that it became by the early 1990s.
Limited Success, Important Stepping Stone
The PC Convertible was not commercially successful — its two-hour battery life, 80C88 processor performance, and high price limited its appeal. But it established IBM’s commitment to laptop computing and provided engineering experience that informed the development of the far more successful IBM ThinkPad series that would arrive six years later.