titude of software. Floppy drives made possible software that never could have existed without them.The next major development in the evolution of the microcomputer was the debut of the IBM PC in 1981. Big Blue did not break any new ground with its machine. In fact they followed very closely to the plan set by Apple. This included an open architecture. They provided five expansion slots to allow for extensive modification and customization of the basic machine. IBM also made available to developers a full set of electrical schematics for the computer and a printout and explanation of the ROM-based Basic Input/Output System (BIOS) which provides the hooks into the machine for hardware and software.IBM approached Bill Gates of Microsoft for a package of languages for their new machine. Being unfamiliar with the microcomputer industry, they also approached Gates for the rights to CP/M, the current industry standard operating system for microcomputers. Gates informed them that CP/M (Control Program for Microcomputers) was not his product, but that they should talk to Gary Kildall of Digital Research Corporation. Digital Research (formerly Intergalactic Digital Research) refused to sign IBM's nondisclosure agreement and so they went back to Microsoft to see if they could develop an operating system for them. Well, they did and the result was the ubiquitous PC-DOS (MS-DOS in the generic form marketed by Microsoft).When the original IBM PC was introduced in August 1981 it came equipped with a 8/16-bit Intel 8088 microprocessor operating at a clock speed of 4.77 MHz, 16K of RAM and a cassette interface and sold for $1265.00, $1565.00 with a Color/Graphics display adapter (CGA). A serious system configured to compete with an Apple II+ came with 48K RAM, one 160K floppy disk drive, PC-DOS and a CGA board. This would set you back $2630.00, slightly less than a 48K Apple II+.The impact of the IBM PC on the microcomputer industry was unprecedented. ...
