BASICS OF COMPUTER SYSTEMS 0-7
of MS-DOS (PC-DOS) and a CGA or monochrome video card. The machine also had a
version of Microsoft BASIC in ROM.
In March 1983, the IBM PC-XT was marketed, with the change being that it had a
hard disk as well. XT stands for ‘Extended Technology’. The next change came about in
August 1984 when the 80286, a 16-bit processor, which also had virtual memory capability,
was used by IBM in its PC. They called it the PC-AT with AT standing for ‘Advanced
Technology’. Then, one after the other, 80386, 80486 and Pentium came to be used in PCs.
The processor developed after the ’486 was to have been named 80586, and Intel wanted
to trademark this number, but a court ruling prevented this. So, the word Pentium was
coined ...