Data General Corporation
Meet Christopher. "He" is a Data General/One, my travelling companion. When I'm away from home, this is the machine that I bring along. He's not exactly a minicomputer, but rather a microcomputer.
The DG/One was the very first of the "laptop" class of Personal Computers now known as PCs. This particular model is the second in the DG/One lineage; the first sported an LCD (Liquid Crystal Display) and either a single or dual 3 1/2" floppy drive.
Chris is a Data General/One Model 2 and has an electroluminescent (EL) display, a single 3.5" floppy drive, and a 10 Mb internal Winchester drive. He weighs in at 13 1/2 pounds minus his power supply (due to the power requirements of the display and hard drive, battery power was considered impractical and therefore was not offered as an option with this model).
The microprocessor "brain" of this machine is a CMOS (Complementary Metal Oxide Semiconductor) rendition of the venerable Intel 8088, known as an 80C88, and runs at a whopping 4 MHz. An option was available for a maths coprocessor (8087), but this machine does not have one.
Main memory is the standard DOS limit of 640 kb, and is comprised of 256 kb on the main CPU board and two removeable cards, one containing 256 kb; the other 128 kb.
The basic I/O ports consist of a standard RS-232 serial line and a Centronics parallel printer port. All serial communications are controlled by 8251 USARTs rather than the more common 8250 UART, implying that the machine is capable of synchronous communications. This particular machine has a built-in 1200 BPS modem and a second RS-232 port. The modem is a Hayes® compatible device and accepts a large subset of the ubiquitous "AT" command set.
The keyboard on this little device, unlike many of his peers, is a delight to use. Even though it is smaller (surprise) than the average desktop PC, the keys offer excellent tactile feel and make a pleasing "click" when depressed. This differs markedly from the newer trend toward membrane keys, or, worse yet, conductive pad technology.
This particular example runs a version of DOS 2.11 that was specially modified by DG for use on the DG/One hardware; a version of CP/M was also available. I don't have the CP/M operating system, though.
Unlike the original Model 1's display, the EL display produces a very readable orange image of 640x480 pixels, and is visible except in absolute full sunlight. If you're ever in the Boston area, require transit via the MBTA's "Red Line", and get one of the 01800- series Bombardier cars, get in the lead car and look at the train status display panel in the cab (it's the one on the left). I think they're the same device.
I have many fond memories bound up with this little machine, not the least
of which was staying up late in a sleeping compartment on Amtrak's
"Crescent" making the last notes of the day in my journal before
retiring for a welcome night's sleep.