Use of CP/M Software
CP/M is a kind of operating system. It tells a computer how to do garden-variety jobs, like moving data from a memory unit to one that does the machine’s electronic reasoning. CP/M isn’t the only operating system that business microcomputers use. When I was writing this chapter, however, it was one of the more common, with variation present on more than half a million computers. A company called Digital Research marketed CP/M, selling to manufacturers, which, in turn, didn’t have to create their own operating systems. In the early 1980s, the big software hits almost always came in CP/M formats.
“We wanted to use CP/M because 10,000 programs were available,” Kay said. They were for computers with 8 bits, not 16—another reason he made the original Kaypro an 8-bitter.
“If we’d used 16 bits,” Kay said with uncharacteristic profanity, “people would have said, ‘Where the hell’s the programs?’ IBM could sell their computers without programs, which is what they did essentially and let the programs come later.”
In contracting software design to outsiders, “Big Blue,” as IBM is called, was defying its own tradition. It hired Microsoft—a Washington State software company headed by a brilliant young Harvard dropout—to create a whole new operating system. Called MS-DOS, the system would become an industry standard by 1984. And from the start, independent software houses hustled to market MS-DOS-style programs usable on the hot new machine for applications like word processing and spreadsheets.
The existing CP/M applications programs wouldn’t work on an unmodified IBM Personal Computer unless the programmers converted them to MS-DOS or another compatible operating system.
‘Two-Disk
They’re the gizmos into which you insert the floppy disks through slots in the computer.
From the outside a disk looks square. It’s inside a container that helps protect it from fingerprints and other threats to the plastic disk’s magnetic coating.
You can’t cover the delicate disk completely, though. Some of it must touch the head of a disk drive. A head “writes” magnetic patterns on the oxide coating of a disk; in other words, it stores information that you’ve typed into your computer or the results of your calculations.