AMSDOS

AMSDOS

Developer	Amstrad
OS family	Disk operating systems
Working state	Discontinued
Source model	Closed source
Initial release	1984(1984)
Default user interface	None, access through BASIC and firmware calls

AMSDOSis adisk operating systemfor the8-bitAmstradCPC Computer(and various clones). The name is a contraction ofAmstradDisk OperatingSystem.

AMSDOS first appeared in 1984 on theCPC 464,with added3 inch diskdrive, and then on theCPC 664andCPC 6128.Relatively fast and efficient for its time, AMSDOS was quicker and more effective than most of its contemporaries.

AMSDOS was provided built into ROM (either supplied with the external disk drive or in the machine ROM, depending on model) and was accessible through the built-inLocomotive BASICas well as throughfirmwareroutines. Its main function was to map thecassetteaccess routines (which were built into every CPC model) through to a disk drive. This enabled the majority of cassette-based programs to work with a disk drive with no modification. AMSDOS was able to support up to two connected disk drives.

Commands

AMDOS extends the AMSTRAD BASIC by the addition of a number of externalcommandswhich are identified by a preceding¦ (bar) symbol.The following is a list of external commands supported by AMSDOS.

• ¦A
• ¦B
• ¦CPM
• ¦DIR
• ¦DISC
• ¦DISC.IN
• ¦DISC.OUT
• ¦DRIVE
• ¦ERA
• ¦REN
• ¦TAPE
• ¦TAPE.IN
• ¦TAPE.OUT
• ¦USER

Alternatives

Other disk operating systems for the Amstrad range includedCP/M(which was also bundled with an external disk drive, or built-in on ROM depending on model), RAMDOS, which allowed the full (800K) capacity of single-density 3 ½ "disks to be used providing a suitable drive was connected andSymbOS.