From:	"Colin W. Glenn" <cwg01 AT gnofn DOT org>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Displaying volumename in prompt
Date:	Thu, 26 Dec 1996 19:26:29 -0600
Organization:	Greater New Orleans Free-Net
Lines:	41
Message-ID:	<Pine.GSO.3.95.961226191042.7656A-100000@sparkie.gnofn.org>
References:	<5974bk$j7e$2 AT tornix DOT tornado DOT be> <19961225 DOT 134311 DOT 4743 DOT 2 DOT chambersb AT juno DOT com>
NNTP-Posting-Host:	sparkie.gnofn.org
Mime-Version:	1.0
In-Reply-To:	<19961225.134311.4743.2.chambersb@juno.com>
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

> >Actually, I wouldn't mind a MSDOS equivalment of MSDOS.  I mean, with 
> >machines we have now, you could convince the system to fold every bit 
> >memory under the 1meg mark.  That means that every application would 
> >able to load and run, one on top of the other.
> Two questions:
> 1)	An MSDOS version of MSDOS?

Ok, ok, bad wording.  What I mean is a operating system which would allow
current programs written for the MSDOS to work, while...>>

> 2)	Would this be with unlimited segments or something?  How else
> would it 'fold'?

Allowing more programs to run within the 640k space allowed for under the
current version of MSDOS.  Yes, 'unlimited segments'.  I've just browsed
the setup on using GDTs and LDTs, so I may stumble here or there but lets
see if I can make this sound right.  Under PM, a segment register becomes
a pointer to a table which the processor uses to access the 'real' address
of the memory block in question, the OS has the GDT setup, and configures
a LDT for every process which it runs.  The only programs which would not
run under this mode would be programs which 'increment' an index register
because this would cause a processor excemption fault.  And there might be
a cure for that as well, the interrupt handler would simply create a new
LDT for a segment which would exist 16 bytes beyond the start of the
segment the program had incremented, load that into the registar and
'RESUME NEXT'.  Of course this should involve the user, ie let him/her
know that:

PROGRAM such-and-such just violated segment integrity,
[C]orrect fault or [A]bort process?

This fault correction could also be incorparated into some type of table
which would bypass this prompt, ie the system knows ahead of time that
this program will cause a fault.  Such an OS would also be able to handle
WIN programs without invoking Windows, it just develops the resources the
programf needs without the user every having to know whether it's a
windows program or not.

Hmmm, tall order.  Might have to void the window service on the beta test.

- Raw text -