IS-DOS

iS-DOS is a disk operating system for Russian ZX Spectrum clones. iS-DOS has been developed in 1990 or 1991, by Iskra Soft (Leningrad, USSR).

It handles floppy disks (double sided, with double density), hard disks, and CD-ROM. Maximum iS-DOS partition size on a hard disk is 16 MiB.

Unlike TR-DOS, iS-DOS is a RAM-based operating system, which reduces amount of memory for user programs.