In what language was MSDOS originally written?
In what language was MSDOS originally written in?
The Wikipedia Article implies either C, QBasic or Pascal, but:
- C was invented to write UNIX, so I don't believe it was used to write MSDOS
- Pascal seems popular to teach programming, but not really popular to write Operating systems in
- QBasic didn't seem to be very popular for Operating Systems at the time MSDOS was developed (or was *BASIC ever very popular to write Operating Systems in it?)
Except these three languages there is also Assembly, but I assume that Microsoft already switched from Assembly to a "higher" level language?
Since C was originally invented for UNIX, I still wouldn't think Microsoft is using C... although the Microsoft API is written in C (I find this kind-of oxymoronic, actually).
Can anyone enlighten me on this topic?
Answer
http://answers.google.com/answers/threadview?id=197874
Since CP/M was written in FORTRAN and QDOS was based on CP/M, does it mean that QDOS and MS-DOS were written in FORTRAN? According to our next article, written by Tim Patterson himself, the assembly language used by Seattle Computer Products wasn't FORTRAN but was built in-house since it was the only thing available to them at that time.
"The last design requirement was that MS-DOS be written in assembly language. While this characteristic does help meet the need for speed and efficiency, the reason for including it is much more basic. The only 8086 software-development tools available to Seattle Computer at that time were an assembler that ran on the Z80 under CP/M and a monitor/debugger that fit into a 2K-byte EPROM (erasable programmable read-only memory). Both of these tools had been developed in house."
"An Inside Look at MS-DOS" http://www.patersontech.com/Dos/Byte/InsideDos.htm