With HXDOS, you can also write a Win32 console-mode program and run it on DOS. 7-zip is an example of a program compatible with HXDOS.
In the context of this tutorial: They use their own "fed" editor.
> a free bug-for-bug compatible version
FreeDOS is significantly different from "real" MS-DOS.
Back in the 20th century I used DR-DOS, written by Digital Research, the company behind the original OS of which DOS was an unauthorised re-implementation.
(DR CP/M-86 was years late, so SCP wrote 86-DOS as a replacement. MS licensed 86-DOS and later bought it. It's not a clone: CP/M was in a compiled high-level language, while 86-DOS was implemented in assembly language, implementing a version of the same API on a different CPU ISA, using a different filesystem drawn from a separate pre-existing product.)
Until MS discontinued MS-DOS and IBM kept on developing it for a few more versions, IBM PC DOS and MS-DOS were near identical.
DR-DOS was a little different from MS-DOS. It had extra commands, used different syntax in the config files, very slightly different output and things -- but then, it was from the original vendor, so that was excusable, and mostly, it understood MS syntax as well.
FreeDOS is not like that. It's quite unlike any other version of DOS. It has differently-named config files, it lives in a differently-named folder with an internal structure, and it has a number of external commands with different names and different syntax. For example, one that threw me is that there is no `SUBST` command, but a different `SWSUBST` which combines the functionality of SUBST and JOIN.
In 21st century DOS terms, at best, FreeDOS is as different from MS/PC/DR DOS as Red Hat is from Debian. In fact it may be more like it to say FreeDOS vs OG DOS is akin to FreeBSD vs Linux.
Some people (and by that I mean Debian people; not sure about anyone else) disagree about OpenWatcom being free software. The license has some unusual requirement(s). There has been talk for a long time about possibly fixing that, but I do not know how on track that is (or how much it matters, in practice): https://github.com/open-watcom/open-watcom-v2/discussions/27...
I ran all the test suites on protected machines. Only when everything was perfect did I run the programs in real mode DOS.
Protected mode memory is the greatest advance ever in computer hardware.
Also, though, you could imagine a system that protected the hard disk from corruption without having to be involved every time the CPU accessed RAM. For example, you could warm-boot into a trusted executive every time you wanted to flush the I/O queue to the hard disk. Rebooting would reload the executive code from the disk and set a "supervisor" bit on the disk interface, which the trusted executive would clear before yielding control back to the untrusted user program.
It seems a bit questionable but not an open-and-shut not-open-source license.
I remember attending a compile panel at one of the SDWest conferences. The panel members were myself, representing Zortech, along with representatives from Borland, Watcom, and Microsoft.
The first question was "do you sell a version that will work on a floppy disk only computer?" One of the other panelists responded with yes, we do. He went on to describe how the various bits could be distributed among multiple floppies, and of course it involved a lot of shuffling floppies in and out.
I was next. I replied, "Yes, we have a version that does it! It costs $200 extra and comes with a hard disk drive!"
That got a huge laugh, and that was the end of that question. I never heard it again from anybody. Sometimes, it's just time to move on!
They were really worth it.
OS/2 ran on the 286 in protected mode. Rational Systems had a 286 protected mode system that we shipped with Zortech. Pharlap had one, too.
I was trying to come up with some advantage of Zortech C that might justify using it now instead of an open-source compiler like DJGPP under some circumstance. Any ideas?
Seems to require Win32 (Digital Mars C/C++ Compiler Version 8.57). Is there a version of the C compiler than can run on FreeDOS or MS-DOS ?