Introduction of IBM PC/AT based on Intel 80286
Introduction of IBM PC/AT based on Intel 80286, featuring VGA graphics
The IBM PC AT was IBM's second generation PC (if you consider the XT an extension of the original PC). It was introduced in 1984 and included several "new" features such as a 6 MHz Intel 80286 processor, a 1.2MB 5.25" floppy drive and an improved keyboard. The typical AT sold with a 20 or 30 MB hard drive and 512K of RAM.
The machine also came with an early version of Microsoft Word and a very early Microsoft Mouse.
The PC AT had a new version of the Microsoft OS: MS-DOS 3.0 which could manage the new 5.25" floppy disk format (1.2 MB), the new hard disk capacities (20 MB and more) and allowed file sharing. It had a new keyboard too (the same we use now, more or less) with cursor keys and a key that could lock it.
Two models were launched: the PC-AT model 1 (256 KB RAM, two floppy disk units and a color screen) and the PC-AT Model 2 (512 KB RAM, one floppy disk unit, one hard disk and a color screen).
This computer was revolutionary, but it was the last time IBM imposed a standard to the PC clone industry. The next year, the first PC based on a 80386 was made by Compaq and IBM failed to impose the PS/2 standard in 1986.
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