| Company / developer | Intel |
|---|---|
| Working state | Historic |
| Source model | closed source |
| Marketing target | exclusively for Intel Microprocessor Development System |
| Available programming languages(s) | Assembler, PL/M |
| Supported platforms | Intel 8080, Intel 8085 |
| License | proprietary (?) |
ISIS is an operating system, created by Intel for their Intel Microprocessor Development System around 1976[1] and adopted as ISIS-II for systems with floppy drives. User interface is Unix-like, even from the program interface point of view, communication with the kernel is this way (i.e., for file opening program should send the name of file and gets back a handle). On the diskette, there was no subdirectory; instead of this, each device has its name, which can be written between a pair of colons (:F0: and :F1: were floppies, :LP: was printer, etc.). ISIS-II has been distributed as part of the Intel Microprocessor Development System and includes standard operating system commands (copy, delete, dir, rename, format)[1] and debugging software (assembler, linker and debugger for external debugging in developed device). There were two editors, one of which, AEdit, contains editing macros support. File editing was provided directly on disk (the .BAK file was always created).
For running ISIS-II, at least 32 kilobytes of RAM was demanded (maximum was 64 kilobytes minus the boot system size). Floppy disk format was 8-inch single density, 250 kB single sided, or 500 kB double sided, later replaced with 5ΒΌ inch double sided single density. Operating system itself was independent of device. Communication with user was terminal-like.