Operating systemsDigital Research CP/M › CP/M 1.4

CP/M 1.4

1976

The 1977 Digital Research release that standardised CP/M across early 8-inch-disk Intel 8080 microcomputers.

Reference & documentation

External technical references for programming CP/M 1.4 and for writing emulators.

ResourceTypeNotes
CP/M 1.3/1.4 Disc & Directory Format (seasip) ↗FormatReverse-engineered 1.4 disc, directory and allocation layout
CP/M Disk and File System Format (cpm8680) ↗FormatDirectory entry and allocation-block format reference
Intel 8080/8085 Assembly Language Programming Manual ↗Instruction set8080 CPU instruction set CP/M 1.4 runs on
CP/M 1.4 System Alteration Guide (Digital Research) ↗Memory mapOfficial BIOS, memory layout, disk-parameter customization
CP/M 1.4 Interface Guide (Digital Research) ↗ProgrammingOfficial spec for calling BDOS and BIOS
CP/M BIOS Entry Points (seasip) ↗ProgrammingBIOS jump table and CP/M 1.x differences
The Programmer's CP/M Handbook (Johnson-Laird) ↗ProgrammingDeep BDOS/BIOS internals and system-programming reference
CP/M BDOS System Calls (seasip) ↗ReferenceBDOS function numbers with CP/M 1.4 specifics
Altair CP/M 1.4 User Guide (Lifeboat) ↗ReferenceAltair distribution CP/M 1.4 user manual
Early Digital Research CP/M Source Code (CHM) ↗SourceDownload original CP/M 1.4 BDOS PL/M source
cpmtools ↗ToolCommand-line utilities to read/write CP/M filesystems
jhallen/cpm emulator and cpmtool ↗ToolHandles 256,256-byte 8-inch CP/M 1.4 images