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MS-DOS 4 Mutli-tasking version?

Chromedome45

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Was there ever such a thing as MS-DOS 4 multitasking version? Kind of an OS/2 pre-cursor? And it was only available in Europe? Just curios.
 
Yes, there is a MS DOS 4.0 version around with a task switcher and some other goods... I think it was not released to public, it was a custom version.
 
It is close to running Windows 1.x without the GUI elements. All the regular DOS applications run in conjunction with PIF files; a rudimentary task switcher (similar to that used in OS/2 1.0) handles them and a handful of DOS 4 New Executable applications. All delightfully wacky.

See http://jsmachines.net/videos/pcjs/ for an example of how it works. Set the virtual disks to DOS 4 M. Use the <ALT> key to enter the task switcher.
 
What brought it to your attention out of curiosity? I'd only been aware of PC-MOS and MP/M for multiuser dos / CP/M. I used to try replacing progman.exe with command.com and was able to have a multitasking dos environment using later windows (3.x) but admittedly it was cumbersome.
 
I think I saw it in Gordon Letwins book Designing OS/2. Just a brief blurb about it.

Wikipedia mentions it:

Apricot Computers pre-announces MS-DOS 4.0, the first multitasking version. Apricot will sell MS-DOS 4.0 to European customers as the controlling program for network servers that support a new family of Apricot microcomputers. Apricot will also offer MS-Net 2, a new version of Microsoft's LAN. Developers and industry insiders expect Microsoft to bypass that version in the United States in favor of a more powerful version, MS-DOS 5.0, which will access up to 16 MB of RAM

Also found this- http://books.google.co.nz/books?id=pzwEAAAAMBAJ&pg=PA6&lpg=PA6&dq=Multi+tasking+ms+dos+4&source=bl&ots=U4QkX-2Fk6&sig=jIUIVjdl_gvIfEKjfsfJm9CKeVI&hl=en&sa=X&ei=O_9kUfv6BoKFiAeLsIFQ&ved=0CCEQ6AEwAjgU#v=onepage&q=Multi tasking ms dos 4&f=false

And this http://www.os2museum.com/wp/?p=1769

Enjoy.
 
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If you inspect the HTML source of the DOS 4.0M emulation page on that site, you'll get nearly all the information you need to download the files. ;)
 
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I see that in the XML this: /disks/pc/dos/microsoft/4.0M/MSDOS400M-DISK1.json" data-value="">MS-DOS 4.0M (Disk 1)</option>
"/disks/pc/dos/microsoft/4.0M/MSDOS400M-DISK2.json" data-value="">MS-DOS 4.0M (Disk 2)</option>

But I am dumb when it comes to xml. So where is the link? If anyone knows how to get the images send me a PM
And then converting a .json back to an image?
 
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The link would be the domain plus the path in the file, so http://<the-site>/disks/pc/ and so on.

-Tor
 
Will do, but tomorrow- I'm not at my computer (mobile device).
What I got downloaded were .json files. I only did a quick test (earlier today).

-Tor
 
Luckily, the author gave the IMG files the exact same name (except the extension) and location, so all you have to do is change these links:
jsmachines.net/disks/pc/dos/microsoft/4.0M/MSDOS400M-DISK1.json
jsmachines.net/disks/pc/dos/microsoft/4.0M/MSDOS400M-DISK2.json
to:
jsmachines.net/disks/pc/dos/microsoft/4.0M/MSDOS400M-DISK1.img
jsmachines.net/disks/pc/dos/microsoft/4.0M/MSDOS400M-DISK2.img
 
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