Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!hplabs!hp-pcd!hpsgpa!plim
From: plim@hpsgpa.HP.COM (Peter Lim)
Newsgroups: comp.sys.ibm.pc
Subject: Re: ramdisks in extended memory, xms, and ems
Message-ID: <340035@hpsgpa.HP.COM>
Date: 29 Nov 89 01:32:29 GMT
References: <436@wjh12.harvard.edu>
Organization: HP Singapore IC Design Ctr
Lines: 32

> Is there any way to decide among setting up ramdisks in plain
> old extended memory, xms extended memory, or ems?
> 
> I have a 286 with 1M on the system board and 4M on a LIM 4.0
> expansion board.  The memory on the expansion board can be con-
> figured as any combination of extended and expanded.  I cur-
> rently have it divided as 2M of each, with the expanded used by
> various applications and the extended all configured as a ramdisk
> (using the ramdrive.sys driver that came with my MS-DOS 3.3).  I
> do not use any applications that require xms.
> 
Well, one thing I do know, if you have true hardware LIM 4.0 (or
even LIM 3.2) you should use expanded memory. Simply by virtue of
smaller CPU overhead. To access expanded memory, you just do some
bank switching and go on from there, whereas to access extended
memory in a 286 machine, you have to reset the CPU after every access
(which must be done in protected mode) to get back to the real mode
where DOS runs.

For RAM disk, print spooler and disk cache, I think PC-KWIK is a
superb product. The disk cache is very fast (especially if you turn
the write-cache option on) and you can share the space among RAM disk,
spooler and cache dynamically !

As a sideline, if you have true hardware LIM 4.0 then you can
do some "true" multitasking using DesqView rather than just using the
EMS to swap program in and out.

Anyway, I have no share in the people who produced PC-KWIK and
DesqView  :-).

Have fun.