IBM PC-AT

UvA Computer Museum catalogue nrs 93.77, 02.01

The PC AT ('Advanced Technology') was introduced by IBM in 1985. It is the first machine in the PC family which was really useful as a workhorse for business and scientific applications. Its expansion bus has been an industry standard (ISA bus) for more than 15 years. The AT keyboard is still the standard for PC's.

Processor 80286 @ 6 MHz, optional 80287 mathematical coprocessor
8-slots expansion bus; 190 W power supply
360 kb and 1.2 Mb 5.25" floppy drives; optional 20 Mb harddisk.
BASIC in ROM

In our museum #93.77, running MSDOS 6, is still in use for driving a variety of terminals, printers, plotters, papertape and magnetic tape equipment.
In this AT the lower (360 Kbyte) floppy drive has been replaced by a 3.5", 1.44 Mb drive for practical reasons. The machine is operated with the Monochrome Display adapter (MDA) and 5151 monitor (the also available Color Graphics Array (CGA) with 5153 monitor has somewhat disappointing image quality). The original 20 MB harddisk is still up and running.
#02.01 is vertically mounted in a 'tower' enclosure. Inside is the Professional Graphics adapter (PGA) driving a 5175 monitor, which combination features 640*480 pixels and 256 colors chosen from a 4096 colors palette, plus a dedicated graphics processor.
The PC-AT, with 1 Mbyte of memory and a 20 Mbyte harddisk, but without adapter and monitor, cost about Dfl 15000 in 1987. The PGA/5175 addition would almost double this price.

The picture of the original PC-AT (shown with 5151 monitor) was taken from a review in Byte, May 1985.
Our AT's were donated by the University's Computer Science department, and Mr. H. Blankensteijn, respectively.
(rev. July, 2013)