These INT21 calls are functionally identical to CP/M.

How to call the OS that is from CP/M.

Com binaries the 100 offset at start. This is because CP/M used a 100 offset.

http://www.fileformat.info/format/com/corion.htm Yep all those .com files are of all things the way CP/M did it executables.

Remove CP/M copied features remove all .com program support. Interesting that what is the interpret called that is right command.com without CP/M stuff that don’t load.

device load added in PC DOS 2.0 was a copy of CP/M device load the left over MDOS feature is interesting to be in dos thinking DOS never went proper multi threaded.

Clarence Moon
“The APIs for MS-DOS were substantially different than those for CP/M”

This is incorrectly. MS-DOS comes substantially different in newer interface post PC DOS 3.0. The old core is CP/M. PC DOS 2.0 new features some are copied from CP/M some are new. The copied ones are on the same call numbers. PC DOS 2.0 was were MS was starting to stand on its own two feet still had not fully at this point. Yes 1.0 is mostly clone.

At the point PC DOS 3.0 DR DOS appears and CP/M pulls in what MS had been doing.

There are many more overlaps.

Wait … wait … no, really, wait …

Nope, still struggling. Can Mr Oiaohm or Mr Pogson enlighten us?

It’d be a bat file. No, it wouldn’t. Maybe a patch to BIOS. Well, probably not. How about something that depends upon INT21? No, that would be later versions of MSDOS.

Well, Mr Oiaohm is probably using it as shorthand for the immense amounts of MSDOS 6.0 that is still sitting around because you just can’t get rid of it. There’s that pesky backwards compatibility again — a problem that Linux, in general, has wisely eschewed.

There are all sorts of bits of MSDOS 6.0 still sitting around.

Oh, wait … there are none whatsoever.

OK Please enumerate which ones that you think that they are.

To fall back on the claim that data structures that may be used internally resemble one another is to say that Open Office and Libre Office are copies of MS Office since they use the same document standards. The APIs for MS-DOS were substantially different than those for CP/M and CP/M-86 and that is what defines the OS. Learn to read. And learn to write. Give us a break.

The data struts of CP/M exist right the way to modern versions of Dos. What remains of QDOS is the construction that was copied from CP/M.

“Paterson designed 86-DOS with an API that was compatible with legacy CP/M programs. At the same time he made a number of changes and enhancements to address what he saw as CP/M’s shortcomings.”

The API is compatible with CP/M it was designed that way. It was a rough clone. Just like Linux made a number of changes to address sort coming in Unix and Posix design.

You ability not to read is also shocking. Addressing shortcomings is what you do when you are cloning.

Note this “very little of QDOS remained.” 1983 fragments of QDOS are still there. They are still there today. Basic API construction you cannot basically change unless you risk breaking every application.

A lot of the QDOS code had to be rewriting because it simply was not quality code that simple.

Just like today in Linux you find very little code of Linux 2.0. You still find it syscalls.

Blood line does not disappear easily.

Heck it directly tells you he copied the CP/M API/ABI so CP/M applications would work.

What is wrong with you Clarence Moon can you not read. Or are you such a poor coder that you never cloned anything so you don’t know what you do when you clone.

At the time IBM got its OS from Microsoft for the XT it was also attempting to source from CP/M who would not give them exclusive deal.

So no Microsoft the XT becomes a CP/M computer. Digital Research becomes the dominate OS maker. There is no OS/2 since there will not be any collaboration between IBM and Digital Research. The clone makers vs IBM starts sooner because Digital Research from before IBM agrees to buy CP/M is selling CP/M to other parties.

1991 when Linux starts the facts will still be about the same for Linus. He wants Unix and its too expensive so he starts Linux. This event will happen in either timeline.

Digital Research is more above board. We are using many different Office suites that are compatible with each other due to no disruption to the standard process. RTF common file format effort was disrupted by Microsoft that event never happens so we have compatibility between office suites. Linux progress has been faster since it was never locked out of the desktop.

There is no windows NT equal either. Since Digital Research is a Unix maker. Linux still crushes Unix as it has.

Sorry without Microsoft. Linux would be the most dominate OS on earth by now. It was also Microsoft who with windows 95 pushed the idea of closed source drivers so hardware did not have to be released with interface spec sheets as well. So Linux driver support today is super without Microsoft in existence.

There is no question that Microsoft only harmed the IT market and Linux growth. Microsoft existing or not has nothing to-do with Linux coming into existence and wiping the floor with the existing unix market. The difference without Microsoft the existing Unix market would be it for competition.

Apple would have fallen to CP/M due to the same reasons. Now it would be Apple and Linux in the final grudge match.

Yes the history map of every point Microsoft stuffed things up makes Microsoft really simple to delete and see no matter what No Microsoft is a good thing.

It was much more than a claim, Mr. Oiaohm, it was a factual demonstration. You know nothing of law, even Australian law. You have some extreme ignorance of the organization and assigning of the Australian Marine Corps, too, if you can remember back that far. Now you demonstrate that you are confused about computer history, too.

From your own cite, since you wish to rely on it for your own assertions, there is the statement:

“Paterson designed 86-DOS with an API that was compatible with legacy CP/M programs. At the same time he made a number of changes and enhancements to address what he saw as CP/M’s shortcomings.”

So, as I said, it was different from the start. Furthermore:

“Microsoft … hired Tim Paterson to port the system to the IBM-PC… IBM watched the developments daily, submitted over 300 change requests before it accepted the product and wrote the user manual for it.”

Which makes it, as I said, a work done to IBM’s direct specifications. Even so, the commercially successful versions of MS-DOS vary from this beginning:

“By 1982, when IBM asked Microsoft to release a version of DOS that was compatible with a hard disk, PC-DOS 2.0 was an almost complete rewrite of DOS, so by March 1983, very little of QDOS remained.”

Apparently your inability to write coherently extends to a similar inability to read the words of others, Mr. Oiaohm. What are you going to do to better yourself?

“MS-DOS was derived from PC-DOS which was a modification of some code purchased by Microsoft to meet an IBM specification document.”

http://en.wikipedia.org/wiki/86-DOS Start reading.

This is QDOS the rough clone of CP/M. Yes that code MS purchased is the link.

Both MS-Dos and PC-Dos are based off the QDOS code base. Yes MS-Dos is a rough clone of CP/M.

“Then the clones, including DR-DOS began to appear and offered pretty good API level compatibility as well as improvements over standard MS-DOS in terms of multi-tasking or memory management or, most often, price.”

DR-DOS is a latter remake of CP/M that 86-DOS(QDOS) was cloned from. Of course DR-DOS should provide prity good API level compatibility since its the master source. If you look at MS-DOS structs you find fragments in there from CP/M support for multi process support that 86-Dos never implemented. So yes dead struct allocation that makes zero sense until you look at CP/M and see that was used for multi process and MS-DOS now uses it for nothing particularly in the dos device structs they are CP/M device structs in fact with space for multi process support.

There is no question at all that MS-Dos and CP/M are related. Very closely in fact file format and internal struts. Closer in a lot of ways than Linux is to Unix. There is no question where the relationship is either. QDOS (Quick and Dirty Operating System) that was renamed to 86-Dos to be more sellable is the relationship point between CP/M and the MS-DOS and PC-Dos operating systems.

DR-Dos, Concurrent DOS and MDos that is a direct branch off the master CP/M. Yes those there contain no 86-dos code. Instead use CP/M code.

You claim I know nothing of Legal. You know bugger all of computer history where software came from Clarence Moon.