MS-DOS 2.0 restoration project

[pdurlej]

A reimplementation of the missing components needed to run MS-DOS 2.0 (MBR, DBR, DOS BIOS, FORMAT, FDISK).

https://www.durlej.net/software.html
https://github.com/p-durlej/dosbios

[bzt]

Nice, good job!

On your site you write that MS-DOS 2.0 is closed-source, this is not true. M$ made it Open Source two years ago, and therefore publicly available:
https://github.com/microsoft/MS-DOS/tre ... 2.0/source

Just for the records, unofficially the work-in-progress source of MS-DOS 6.0 is out too (so this is actually 5.0 with some advancements):
ftp://oscollect.old-dos.ru/Abandonware/ ... e_Code.zip

Cheers,
bzt

[pdurlej]

On your site you write that MS-DOS 2.0 is closed-source, this is not true.

Nope. The closed source IBMBIO.COM is a component of PC DOS and, AFAIK, is not redistributable.

Additionally, AFAIK, there was not any opensource (or even redistributable) counterpart of IBMBIO.COM (IO.SYS in MS-DOS naming convention).

[bzt]

Nope. The closed source IBMBIO.COM is a component of PC DOS and, AFAIK, is not redistributable.

Additionally, AFAIK, there was not any opensource (or even redistributable) counterpart of IBMBIO.COM (IO.SYS in MS-DOS naming convention).

Strictly speaking IBMBIO.COM / IO.SYS is not part of the OS, as it provides and abstraction layer and interface to the firmware (BIOS). In theory you could run DOS on a non-IBM-PC compatible if you provide an IO.SYS for that machine (never happened as far as I know). All the rest is Open Source (including MSDOS.SYS and FORMAT etc.), so I think MS-DOS 2.0 is indeed Open Source. Regardless your IO.SYS implementation is cool, it is good we have an Open Source alternative for that too!

Cheers,
bzt

[Octocontrabass]

In theory you could run DOS on a non-IBM-PC compatible if you provide an IO.SYS for that machine (never happened as far as I know).

It happened a few times before IBM-compatible hardware completely took over. Perhaps the biggest example is the NEC PC-98 series, which wasn't discontinued until 2003. You can find a copy of MS-DOS 6.2 for PC-98 pretty easily.

[iansjack]

In theory you could run DOS on a non-IBM-PC compatible if you provide an IO.SYS for that machine (never happened as far as I know).

It has happened. Some (if not all) Apricot computers were not fully compatible and so required a special version of DOS (basically of those files). I have (somewhere) an Apricot Portable to which this applied. I even had to patch Turbo Pascal to get it to function correctly.

I believe that some early Compaqs also needed a special keyboard driver.

[pdurlej]

The MS-DOS 2.0 restoration project files have been updated:
- the ATTRIB command has been implemented (although it is currently limited to displaying file attributes)
- FDISK has been extended and is more like the IBM version
- MODE command from MS-DOS 1.25 is included
- several bugs were fixed