SpartaDOS X
| Command prompt (4.42-beta) | |
| Developer | ICD, Inc. (4.0-4.21) Fine Tooned Engineering (4.22) DLT (since 4.31) | 
|---|---|
| Written in | 6502 assembler | 
| OS family | SpartaDOS X | 
| Working state | Current | 
| Source model | Closed source | 
| Initial release | 1988 | 
| Latest release | 4.50 / December 23, 2024 | 
| Latest preview | 4.49g / January 9, 2022 | 
| Available in | English | 
| Platforms | Atari 8-bit | 
| Influenced by | MS-DOS | 
| Default user interface | Command-line interface | 
| License | Proprietary | 
| Official website | spartados | 
SpartaDOS X (or SpartaDOS 4.0) is a disk operating system for the Atari 8-bit computers that closely resembles MS-DOS. It was developed and sold by ICD in 1987-1993, and many years later picked up by the third-party community SpartaDOS X Upgrade Project, which still maintains the software.