IBM Portable Personal Computer

The IBM Portable Personal Computer 5155 model 68 was an early portable computer developed by IBM after the success of Compaq's suitcase-size portable machine (the Compaq Portable). It was released in February, 1984, and was eventually replaced by the IBM Convertible.

The Portable was basically a PC/XT motherboard, transplanted into a Compaq-style luggable case. The system featured 256 kilobytes of memory (expandable to 512 kB on the motherboard), an added CGA card connected to an internal monochrome amber composite monitor, and one or two half-height 5¼" 360 kB floppy disk drives. Unlike the Compaq Portable, which used a dual-mode monitor and special display card, IBM used a stock CGA card and a 9" amber monochrome composite monitor, which had lower resolution. It could, however, display color if connected to an external monitor or television. A separate 83-key keyboard and cable was provided.

If a bit less sophisticated than the Compaq Portable, IBM's machine had the advantage of a lower price tag. The motherboard had eight expansion slots. The power supply was rated 114 watts and was suitable for operation on either 120 or 230 VAC. Hard disks were a very common third-party add-on as IBM did not offer them from the factory. Typically in a two-drive context, floppy drive A: ran the operating system, and drive B: would be used for application and data diskettes.

Its selling point as a "portable" was that it combined the monitor into a base unit approximating a medium-sized suitcase that could be simply set on its flat side, plugged in, the keyboard folded down or detached, and booted up for use, though printers at the time, if needed, still tended to be less "portable".