What language was MSDOS written in?

Question

What language was MSDOS written in?

A Wikipedia article implies C, QBasic, or Pascal, but:

• C was invented for writing UNIX, so I don’t think it was used to write MSDOS
• Pascal seems popular for teaching programming, but not very popular for writing operating systems in
• QBasic does not seem to be very popular for operating systems at the time MSDOS was developed (or was * BASIC ever very popular for writing operating systems in it?)

In addition to these three languages, there is also Assembly, but I assume that Microsoft has already switched from Assembly to a higher level language?

Since C was originally invented for UNIX, I still don’t think Microsoft uses C ... although the Microsoft API is written in C (I find this kind of oxymoronic, actually).

Can someone enlighten me on this topic?

Answer 1

http://answers.google.com/answers/threadview?id=197874

Since CP / M was written in FORTRAN and QDOS was based on CP / M, does this 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 was not FORTRAN, but was built on it was the only one available at that time.

“The last design requirement was that MS-DOS is written in the assembly language. Although this feature helps satisfy the need for speed and efficiency, the reason for including it is much more thorough. The only 8086 Seattle computer software development tool was at that time "which worked on the Z80 under CP / M and a monitor / debugger that fit in a 2K-byte EPROM (erasable programmable read-only memory). Both of these tools were developed in-house."

"An Inside Look at MS-DOS" http://www.patersontech.com/Dos/Byte/InsideDos.htm

Answer 2

Well, MS-DOS was originally renamed 86-DOS, and 86-DOS was written in the build, if I'm not mistaken, so that will make ASM the source language for MS-DOS.

Answer 3

As indicated at http://www.patersontech.com/Dos/Byte/InsideDos.htm

"The last design requirement was that MS-DOS is written in assembly language."

(Note that during the build many appeals were collected, not just parts of the operating system).

Answer 4

See timeline

• Assembler Source from 86DOS
• Documentation

Answer 5

The preliminary dates are Unix MS-DOS, so this is not an obstacle to programming it under C. But I would go to the assembly for most parts at least ...

Answer 6

If you are looking for MS-DOS on some websites, you can find version 6 with source code included. It was written in assembler and there is no C code at all. All utilities, the kernel and even the installer were written in assembler.

And regarding Windows, it has a lot of assembly language on it, but some parts that are written in C, and then in C ++.