A report on CP/M

A screenshot of CP/M-86
CP/M advertisement in the 29 November 1982 issue of InfoWorld magazine
Apple CP/M Card with manual
CP/M Plus (CP/M 3) System Guide
DEC PRO-CP/M-80 floppy-disk distribution for the Z80-A co-processor in a DEC Professional 3xx series
Sanco 8001 computer, running under CP/M 2.2 (1982)
CP/M cartridge for the Commodore 64
Screenshot showing a CP/M 3.0 directory listing using the command on a Commodore 128 home computer
CP/M advertisement in the 11 December 1978, issue of InfoWorld magazine
Distribution 5 1/4 inch diskettes and packaging for the last version (version 4) of WordStar word processing program released for 8-bit CP/M
MBASIC text output displayed on a monochrome monitor typical for that time.
CP/M derivate SCP running on an East German robotron PC 1715
CP/J version 2.21 running on an Elwro 804 Junior

Mass-market operating system created in 1974 for Intel 8080/85-based microcomputers by Gary Kildall of Digital Research, Inc. Initially confined to single-tasking on 8-bit processors and no more than 64 kilobytes of memory, later versions of CP/M added multi-user variations and were migrated to 16-bit processors.

- CP/M
A screenshot of CP/M-86

109 related topics with Alpha

Overall

Screenshot showing the boot screen, command-line interface, and directory structure of MS-DOS 6

DOS

17 links

Platform-independent acronym for "disk operating system" that later became a common shorthand for disk-based operating systems on IBM PC compatibles.

Platform-independent acronym for "disk operating system" that later became a common shorthand for disk-based operating systems on IBM PC compatibles.

Screenshot showing the boot screen, command-line interface, and directory structure of MS-DOS 6
Screenshot showing the boot screen, command-line interface, version information, and directory structure of FreeDOS
Screenshot showing Digital Research Apple CP/M on a Z-80 SoftCard for the Apple II
The IBM Personal Computer (IBM 5150 PC)
A sample SCP 86-DOS session (simulated)
Digital Research CP/M-86 for the IBM Personal Computer Version 1.0
OS/2 1.0 featured a text mode interface similar to MS-DOS.
DOSBox
Arachne web browser

IBM PC DOS (and the separately sold MS-DOS) and its predecessor, 86-DOS, was developed to be similar to Digital Research's CP/M—the dominant disk operating system for 8-bit Intel 8080 and Zilog Z80 microcomputers—but instead ran on Intel 8086 16-bit processors, in order to easily port CP/M applications to MS-DOS.

A Z80 manufactured in June 1976 according to the date stamp

Zilog Z80

19 links

8-bit microprocessor introduced by Zilog as the startup company's first product.

8-bit microprocessor introduced by Zilog as the startup company's first product.

A Z80 manufactured in June 1976 according to the date stamp
The Z80's original DIP40 chip package pinout
A May 1976 advertisement for the Zilog Z-80 8-bit microprocessor
Photo of the original Zilog Z80 microprocessor design in depletion-load nMOS. Total die size is 3545×3350 μm. (This actual chip manufactured in 1990.)
A CMOS Z80 in a Quad Flat Package
An approximate block diagram of the Z80. There is no dedicated adder for offsets or separate incrementer for R, and no need for more than a single 16-bit temporary register WZ (although the incrementer latches are also used as a 16-bit temporary register, in other contexts). It is the PC and IR registers that are placed in a separate group, with a detachable bus segment, to allow updates of these registers in parallel with the main register bank.
The Z80A was used as the CPU in a number of gaming consoles, such as this ColecoVision.
A Sinclair ZX Spectrum which used a Z80 Clocked at 3.5 MHz
Z80-based PABX. The Z80 is the third chip from the left, to the right of the chip with the hand-written white label on it.
PIO Z84C2008
CTC Z84C3008
SIO Z84C4008
Mostek Z80: MK3880
NEC μPD780C
Sharp LH0080
Toshiba Z84C00
East Germany RFT U880D
Soviet T34BM1 Z80 clone
ASCII R800
Hitachi HD64180
Zilog Z180
Zilog Z280
Toshiba TMPZ84C015

Faggin designed the instruction set to be binary compatible with the Intel 8080 so that most 8080 code, notably the CP/M operating system and Intel's PL/M compiler for 8080 (as well as its generated code), would run unmodified on the new Z80 CPU.

The command-line interface, showing that the current directory is the root of drive C

MS-DOS

16 links

Operating system for x86-based personal computers mostly developed by Microsoft.

Operating system for x86-based personal computers mostly developed by Microsoft.

The command-line interface, showing that the current directory is the root of drive C
MS-DOS command prompt
MS-DOS (Compaq-DOS) version 1.12 (based on MS-DOS 1.25) for Compaq Personal Computer
MS-DOS 2.11 boot disk for the Leading Edge Model D in its sleeve
MS-DOS 3.3C for the PC-9800 series
MS-DOS version 5.0
German MS-DOS 6.2 Update
MS-DOS version 6.22
Japanese MS-DOS 6.2/V
The original MS-DOS advertisement in 1981
MS-DOS Prompt in Windows 95
Command Prompt in Windows 10
, MS-DOS is still used in some enterprises to run legacy applications, such as this US Navy food service management system.

Development of 86-DOS took only six weeks, as it was basically a clone of Digital Research's CP/M (for 8080/Z80 processors), ported to run on 8086 processors and with two notable differences compared to CP/M: an improved disk sector buffering logic, and the introduction of FAT12 instead of the CP/M filesystem.

Digital Research

12 links

Digital Research, Inc. (DR or DRI) was a company created by Gary Kildall to market and develop his CP/M operating system and related 8-bit, 16-bit and 32-bit systems like MP/M, Concurrent DOS, FlexOS, Multiuser DOS, DOS Plus, DR DOS and GEM.

An Intel C8080A processor variant with white ceramic package, solder seal metal lid, and gold pins.

Intel 8080

12 links

Second 8-bit microprocessor designed and manufactured by Intel.

Second 8-bit microprocessor designed and manufactured by Intel.

An Intel C8080A processor variant with white ceramic package, solder seal metal lid, and gold pins.
i8080 microarchitecture
8080 Pinout
AMD Am9080
CEMI MCY7880 (Poland)
Kvazar Kiev K580IK80 (Soviet Union)
Mitsubishi Electric M5L8080
National Semiconductor INS8080
NEC μPD8080AF
OKI MSM8080
Siemens SAB8080
Signetics MP8080
Tesla (Czechoslovak company) MHB8080
Texas Instruments TMS8080

Several factors contributed to its popularity: its 40-pin package made it easier to interface than the 18-pin 8008, and also made its data bus more efficient; its NMOS implementation gave it faster transistors than those of the P-type metal-oxide-semiconductor logic (PMOS) 8008, while also simplifying interfacing by making it TTL-compatible; a wider variety of support chips were available; its instruction set was enhanced over the 8008; and its full 16-bit address bus (versus the 14-bit one of the 8008) enabled it to access 64 KB of memory, four times more than the 8008's range of 16 KB. It was used in the Altair 8800 and subsequent S-100 bus personal computers until it was replaced by the Z80 in this role, and was the original target CPU for CP/M operating systems developed by Gary Kildall.

DeviceLogics DR-DOS 8.0

DR-DOS

12 links

Disk operating system for IBM PC compatibles.

Disk operating system for IBM PC compatibles.

DeviceLogics DR-DOS 8.0
Front and rear views of the Carry-I book-sized diskless workstation, bundled with DR DOS 5.0, based on an Intel 80286 processor and produced by Taiwan's Flytech Technology c. 1991
Digital Research DR DOS 6.0 startup disk
Novell DR DOS 6.0 manual
A typical command line in Novell DOS 7

Digital Research's original CP/M for the 8-bit Intel 8080- and Z-80-based systems spawned numerous spin-off versions, most notably CP/M-86 for the Intel 8086/8088 family of processors.

MP/M

10 links

MP/M (Multi-Programming Monitor Control Program ) is a discontinued multi-user version of the CP/M operating system, created by Digital Research developer Tom Rolander in 1979.

A screenshot of CP/M-86 for the IBM PC/XT/AT Version 1.1

CP/M-86

10 links

A screenshot of CP/M-86 for the IBM PC/XT/AT Version 1.1
Digital Research CP/M-86 for the IBM Personal Computer Version 1.0

CP/M-86 was a version of the CP/M operating system that Digital Research (DR) made for the Intel 8086 and Intel 8088.

OS/360 was used on most IBM mainframe computers beginning in 1966, including computers used by the Apollo program.

Operating system

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System software that manages computer hardware, software resources, and provides common services for computer programs.

System software that manages computer hardware, software resources, and provides common services for computer programs.

OS/360 was used on most IBM mainframe computers beginning in 1966, including computers used by the Apollo program.
PC DOS was an early personal computer OS that featured a command-line interface.
Mac OS by Apple Computer became the first widespread OS to feature a graphical user interface. Many of its features such as windows and icons would later become commonplace in GUIs.
The first server for the World Wide Web ran on NeXTSTEP, based on BSD.
Ubuntu, desktop Linux distribution
Linux, a unix-like operating system was first time released on September 17, 1991, by Linus Torvalds. Picture of Tux the penguin, mascot of Linux.
A kernel connects the application software to the hardware of a computer.
Privilege rings for the x86 microprocessor architecture available in protected mode. Operating systems determine which processes run in each mode.
Many operating systems can "trick" programs into using memory scattered around the hard disk and RAM as if it is one continuous chunk of memory, called virtual memory.
File systems allow users and programs to organize and sort files on a computer, often through the use of directories (or "folders").
A screenshot of the Bash command line. Each command is typed out after the 'prompt', and then its output appears below, working its way down the screen. The current command prompt is at the bottom.
A screenshot of the KDE Plasma 5 graphical user interface. Programs take the form of images on the screen, and the files, folders (directories), and applications take the form of icons and symbols. A mouse is used to navigate the computer.

One notable early disk operating system was CP/M, which was supported on many early microcomputers and was closely imitated by Microsoft's MS-DOS, which became widely popular as the operating system chosen for the IBM PC (IBM's version of it was called IBM DOS or PC DOS).

A sample 86-DOS session (simulated).

86-DOS

13 links

Discontinued operating system developed and marketed by Seattle Computer Products (SCP) for its Intel 8086-based computer kit.

Discontinued operating system developed and marketed by Seattle Computer Products (SCP) for its Intel 8086-based computer kit.

A sample 86-DOS session (simulated).
A sample 86-DOS session (simulated).

86-DOS shared a few of its commands with other operating systems like OS/8 and CP/M, which made it easy to port programs from the latter.