US-DOS or other MS-DOS Emulator

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US-DOS or other MS-DOS Emulator

I have an apple //e and I'd like to see if I could get windows 1 on it, just for fun(also some games I have are for MS-DOS). I have found out that there does exist an MS-DOS emulator called US-DOS. However, I've not been able to find the file for it. All the links I've found that are supposedly a download, point to websites that don't exist anymore. If anyone could help with a current link or file, I'd be very grateful. Also if there is, for whatever reason, another emulator that I could instead get my hands on, again, a file or link would be great.

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Re: US-DOS or other MS-DOS Emulator

APPLE ][+ US DOS Version 1.11

I see your reply to a discussion on USENET.

Back in the early 1990-ies a student from Bulgaria created MS-DOS alike Operating System for Pravetz 82/8A/8C/8M (Apple II clones), called US-DOS (Universal Software DOS)

I tried it out, and it is pretty cool.

You can run Apple II programs from US DOS: 6502 binary programs, and Applesoft BASIC programs. The commands are similar to MS-DOS: DIR, CD, etc. The command to get out of Applesoft BASIC and back into US DOS is SYSTEM.

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Re: US-DOS or other MS-DOS Emulator

Here is the video showing how it works.

https://www.youtube.com/watch?v=k0cP0tfKuLI

The video has a link to the file but that is incorrect.
The correct link for the file is:

http://mirrors.apple2.org.za/ftp.apple.asimov.net/images/masters/other_os/

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Re: US-DOS or other MS-DOS Emulator

Thanks guys, this really helps!

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Re: US-DOS or other MS-DOS Emulator

Welcome to the forum, Andrew!

In your first post you mentioned that you like to run windows 1 and some games on the Apple II. I'm afraid that won't be possible, since US-DOS is only an OS that has commands like MS-DOS. Running games and Windows requires a x86 CPU.

Like on the Apple II, for performance, both types of software frequently talk to the CPU and the rest of the hardware directly, instead of using OS calls.

Additionally almost all of this early pc software is written in assembly, so even if you had the sources, it would be impossible to recompile without rewriting it completely.

However, have fun with your IIe, there are plenty of good games for it!

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Re: US-DOS or other MS-DOS Emulator

"I'm afraid that won't be possible"

I was very surprised to find US-DOS (1991), a MS-DOS like program for the Apple II. If anything the Apple II has taught me, is that anything is possible ...

"Additionally almost all of this early pc software is written in assembly, so even if you had the sources, it would be impossible to recompile without rewriting it completely."

The few expensive compilers from that era were flaky, and you were probably better off rewriting the slow parts in assembly. Apple II software was rewritten in assembly to run on the PC.

"Running games and Windows requires a x86 CPU."

Not really. Software can be ported, cross-compiled, simulated, emulated. Running Robotron in AppleWin an Apple II emulator under Wine on a Linux distro inside a virtual box running on Mac OS running in a container compiled with gcc running on Windows10, ... keep going... Microsoft has ported their software to many other CPUs and platforms.
Windows 1.01 came out in 1985 the same year Microsoft Word was ported to the Macintosh from MS-DOS -- Microsoft began developing their graphical interface in 1981, the same year the first IBM PC was sold. It shouldn't be too difficult to run "Reversi" from US-DOS running natively on the Apple II. There are many versions of Othello for the Apple II, and whatever primitive games that could be launched from MS-DOS Executive. Arcade games, and precursors of games to come for the PC already ran on the Apple II. Given Apple's lawsuit against Microsoft at the time, I doubt that running (or publishing) a Windows 1.0 look-alike on the Apple II would have been a very smart thing to do at the time. There are GUI environments for the Apple II.

The (1977) Apple II already had a mountain of software available for it which would include many many native Apple II versions of all of this early pc software. You can launch all of this software from US-DOS on the Apple II if that's what you want to do. Anything is possible.

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Re: US-DOS or other MS-DOS Emulator


Windows 1.01 came out in 1985 the same year Microsoft Word was ported to the Macintosh from MS-DOS

The development of Word took place on the Mac, even Word for Windows. In 1996 the development changed to M$ Windows. And everybody learnt all he should know about the quality of Windows software.


-- Microsoft began developing their graphical interface in 1981, the same year the first IBM PC was sold.

In November 1985 M$ started selling Windows 1.0 but nobody was interested. The first success of Windows was 3.0 in 1990, the same year Apple published System 7.

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Re: US-DOS or other MS-DOS Emulator

I believe Andrew's original question was if you could run PC programs on an apple II.

MS-DOS is, like ProDOS, much more than just DIR, CD, etc. on the command line. It has, like every operating system, internal routines that may be called by programs to handle memory, input/output and so on.

Even if US-DOS provided exactly these calls, it still won't be possible to run the 16bit x86 PC binaries, because the 8bit 6502 is a completely different processor. It is the same as you can't run PPC apps on a 68k Mac, even if it is the 'same' MacOS. (the other way around is only possible, because the PowerPC processor has inbuilt 68k-emulation)

Of course it is possible to write a x86 emulation, but that would be incredibly slow and unusable.

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Re: US-DOS or other MS-DOS Emulator

I get what you are saying. You believe that there is a need to run 8086/8088/80286 binaries on the Apple II, but 6502 binaries for similar programs exist and quite a mountain of programs I might add. Some 6502 binaries were rewritten for the 4 MHz 8086/8088 PC.

The commands in US-DOS are similar to MS-DOS, so for someone familiar with those commands, it might be easier to use than Apple DOS 3.3 or ProDOS. Try running US-DOS as I did, and you can type MARIO and it launches the Apple II 6502 binary of the arcade game.

I believe you are right about MS-DOS, a "Disk" Operating System, providing some facilities to handle memory, and input/output, but not much else. Programs didn't need much else, other than ways to LOAD, SAVE and RUN. Many programs like games once launched effectively take over the machine and no longer need or want those facilities resident. It wouldn't be much of a stretch to recreate a MS-DOS Executive-like program for the Apple II, it didn't seem to do much else other than launch programs, later versions of Windows after 1.01 obviously got more features.

I believe you are wrong about the PowerPC processor having inbuilt 68k-emulation.

Apple, which also lacked a PowerPC based OS, took a different route. Utilizing the portability platform yielded by the secret Star Trek project, the company ported the essential pieces of their Mac OS operating system to the PowerPC architecture, and further wrote a 68k emulator that could run 68k based applications and the parts of the OS that had not been rewritten.
https://en.wikipedia.org/wiki/PowerPC#Implementations

> Of course it is possible to write a x86 emulation, but that would be incredibly slow and unusable.

Emulation might be one way to do it and obviously it might be slower, it depends on the program. My point is all of those early PC programs and many more were already available as 6502 binaries on the Apple II.

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