DOS Plus
DOS Plus (erroneously also known as DOS+) was the first operating system developed by Digital Research's OEM Support Group in Newbury, Berkshire, UK, first released in 1985. DOS Plus 1.0 was based on CP/M-86 Plus combined with the PCMODE emulator from Concurrent PC DOS 4.11. While CP/M-86 Plus and Concurrent DOS 4.1 still had been developed in the United States, Concurrent PC DOS 4.11 was an internationalized and bug-fixed version brought forward by Digital Research UK. Later DOS Plus 2.x issues were based on Concurrent PC DOS 5.0 instead. In the broader picture, DOS Plus can be seen as an intermediate step between Concurrent CP/M-86 and DR DOS.
Digital Research DOS Plus Version 1.2 | |
| Developer | Digital Research |
|---|---|
| OS family | CP/M-86 |
| Working state | Discontinued |
| Source model | Closed source |
| Initial release | 1985 |
| Latest release | DOS Plus 2.1 (with BDOS 5.0) |
| Available in | English |
| Platforms | Intel 8086, Intel 80186 |
| Kernel type | Monolithic kernel |
| Default user interface | Command-line interface (COMMAND.COM) |
| License | Proprietary |
| Preceded by | CP/M-86 Plus |
| Succeeded by | DR DOS |
DOS Plus is able to run programs written for either CP/M-86 or MS-DOS 2.11, and can read and write the floppy formats used by both of these systems. Up to four CP/M-86 programs can be multitasked, but only one DOS program can be run at a time.