Path: utzoo!utgpu!watmath!clyde!att!poseidon!psrc
From: psrc@poseidon.ATT.COM (Paul S. R. Chisholm)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Is AT mainboard RAM useful above 1M?
Summary: RAM disks, disk caches, extended vs. expanded
Message-ID: <592@poseidon.ATT.COM>
Date: 20 Nov 88 22:58:38 GMT
References: <2663@orca.TEK.COM> <7329@pasteur.Berkeley.EDU> <2105@spdcc.COM> <1717I78BC@CUNYVM>
Organization: AT&T Bell Laboratories
Lines: 30

<"He seemed like such a nice man . . . and then he turned out to be a writer!">

In <1717I78BC@CUNYVM>, I78BC@CUNYVM.CUNY.EDU (Michael Polymenakos) writes:
>  I've found Ramdisks to be of little use in a real-life environment (unless
> it is a *BIG* ramdisk ).

A RAM disk is better than a disk cache for temporary files, unless
you've got a write-into cache (rare under MS-DOS).  Using a RAM disk
lets you specify what files you'd like cached (e.g., libraries, include
files, programs you run frequently for short periods of time).
 
> What? Got a fast hard disk? Doing lotsa disk writes? A print-spooler
> might be a better use for it...

Indeed.
 
> One question. Can extended RAM be used as expanded? Sounds unlikely,
> i know...

It's possible (but slow) to simulate LIM EMS in 286 extended memory.
It's easy (and fast) to simulate LIM EMS in 386 extended memory (e.g.,
386-Max or QEMM), or for 286 extended memory cards with special
hardware (e.g., QEMM for the PS/2-50 and -60).

However, with the proliferation of 286 boxes, more and more software
can now use extended memory in addition to expanded memory.

Paul S. R. Chisholm, psrc@poseidon.att.com (formerly psc@lznv.att.com)
AT&T Bell Laboratories, att!poseidon!psrc, AT&T Mail !psrchisholm
I'm not speaking for the company, I'm just speaking my mind.