Cp/M Operating System by Digital Research

CP/M Operating System by Digital Research



History of CP/M 3
History of the Personal Computer 3
Who was Gary Kidall? 4
CP/M – OS 5
User interface 6
File Management 6
Device Management 8
The Disk Drive - BIOS versus BDOS 8
Memory Management 9
Communication Services 10
About the CP/M museum online for further research 11
Reference 12

History of CP/M
History of the Personal Computer
The first microprocessor chip was created in 1968 by the Intel Corporation. The 4-bit chip, 4004, was designed for the Busicom 1141-PF calculator. This lead to the first personal computer, the Mark-8, designed in 1974, based on the 8-bit Intel 8080 chip. 1975 brought the first assembled personal computer named the Altair 8800 from Micro Instrumentation and Telemetry Systems (MITS); it was based on the 8080 chip, but had no keyboard or display. The first useful microcomputer was the IMSAI 8080, which was targeted for small business users, had a floppy drive and used the CP/M operating system developed by Gary Kildall while working at Intel, but then Gary and his wife Dorothy founded Intergalactic Digital Research, Inc to market and sell CP/M as the first microprocessor operating system. Tandy (Radio Shack) then introduced the TRS-80 which used CP/M to control the 8080 processor clone (the Zilog Z-80). In 1976, two companies changed there names, the first was Intergalactic Digital Research, Inc to Digital Research, Inc, and the second was Traf-O-Data to Microsoft. While Digital Research worked on developing the CP/M operating system, Microsoft worked on programming languages for computers using the Intel and Tandy chips and the CP/M operating system. In 1979 Intel introduced the 8088/8086 16-bit microprocessor. Tim Patterson at Seattle Computer Products, instead of waiting for Digital Research to release its 16 bit version of CP/M, wrote QDOS using Microsoft’s Altair Disk BASIC, which was mostly a copy of CP/M with a new file and disk management features. In 1980,... [continues]

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