Re: Disk I/O, BIOS, dosemu, FreeDOS, linux host with Virtual Machines

Bob Masta wrote:
On Sun, 24 Feb 2008 22:28:45 GMT, Frank Kotler <spamtrap@xxxxxxxxxx>
wrote:


Pop Tart wrote:

Hello,

I've come to a point in my study of MASM where I can't work the examples for
disk I/O unless I have Windows 98 or less.

<snip>

I'm not sure why you'd want Win98. I know it comes with "real dos", but in a "dos box", the bios interrupts are "fake" (I mean "emulated"). I think you'd want "real bios interrupts",


I assume the OP said "Win98 or less" because you can get to
real-mode DOS. It's a little more cumbersome than just using the "DOS box" you get when you click on the MS-DOS option. You
can get to real-mode via "Start - Shutdown - Restart the computer in MS-DOS mode", or you can create a desktop icon that automatically
goes to real-mode, runs your app, and then restarts Windows. You
can't do either of those in later Windows versions (except WinMe,
with some trickery).

Yeah... I'm not so sure about "restart in dos mode". Type "exit", and IIRC you wind up back in Windows. Not what I call "real dos", but it probably is "real" enough for bios interrupts (not "real" enough for Flat Real Mode, IIRC).

You can hit some function key... F5? F8? during bootup, or what i did - edit msdos.sys. It's just a text file - didn't used to be, in the good old days. If you change "GUI=1" to "GUI=0" - "real dos". If you want the GUI, type "win". Before you can edit msdos.sys, you've gotta remove some "attributes" from it - system, hidden and readonly. "attrib -s -h -r msdos.sys" - put 'em back when you're done when you're done, if you feel like it. This used to be "everybody knows"... I suppose it's in danger of becoming "forgotten lore"...

If we're stuck with "greater than" Win98, where the dos box "doesn't smell right", and if we've got a floppy drive, we might be interested in this:

http://mikegonta.com/dosboots

(opendos, or similar, ought to be fine, too)

Maybe could make a bootable CD out of it, too(?).

Best,
Frank

.

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