Date   : Thu, 19 May 1983 02:49:00 EDT
From   : Ronald G. Fowler <RGF@mit-mc.arpa>
Subject: [RGF: How to use Mem. mapping.]

Date: 19 May 1983 02:47 EDT
From: Ronald G. Fowler <RGF>
To:   Thieret.WBST at PARC-MAXC
cc:   RGF
Re:   How to use Mem. mapping.

  The solution almost universally employed is to set up a chunk of
memory as "global" -- ie, it responds only to the low 16 address
lines, ignoring the extended lines, and therefore always "on".

The size of this global memory depends on the application -- it may
be small enough only to hold an inter-bank communication routine,
or (as in the case of a banked MP/M system, for example) may be
as large as 16K, 20K or more.          --Ron Fowler