Re: increase base memory

[Stas Sergeev <stssppnn@yahoo.com>]

Hello.

kandan bala wrote:
> I came to know the dosemu reserves A000 segment
> reserved for graphics.
> Is it possible to shift OR  change another segment
> for graphics.
Ralf Brown memory.lst states:
--------V-MA0000000--------------------------
MEM A000h:0000h - EGA+ GRAPHICS BUFFER
Size:	65536 BYTEs

So it was always there. QEMM have a
program called "vidram", which allows
to use that region as a base memory
by the cost of not being able to diplay
graphics, but vidram will not work
under dosemu because qemm itself doesn't
work under dosemu.

> Is it logically correct.
But how are you running your program
at a pure dos at first (i.e. not
under linux/dosemu)? If your program
works only with QEMM's vidram or something
similar, then your program is broken
at a first place.
Dosemu allows you to use both UMB and
HMA, so there should be no disadvantages
against the pure dos (except that QEMM
with all its wonderfull tricks can't
be used).

> and running a cobol application.
I don't know what cobol was used, but
if it is a MicroFocus cobol, they
provide a DOS extender for it called xm,
wich will let the program to use all
the memory available for DPMI.

Increasing the base memory above 640Kb
is definitely the bad idea, as it is
used very rarely even in a pure DOS
and will cost you the inability to
display graphics.