Date   : Wed, 22 Dec 1982 08:35:00 PST
From   : Eldridge.ES@Parc-Maxc
Subject: Re: USER # in BIOS

The error you describe is common to many CBIOS implementations and is an
annoying bug.  The proper solution is to save the value at location 4 and
use it
as the currently logged drive on a warm boot.  Location 4 contains both the
current logged-in drive and the user number.  The warm boot routine should
save location 4, read in the CCP, then put the saved location 4 value into
the C
reg and jump to the CCP.

Another idea I have been toying with is to run a checksum on the CCP
whenever a warm boot is requested, and only load the CCP if it has been over-
written.  This would have the advantage that ^C would log-in a new disk even
if the disk did not have CP/M on it (providing, of course, that the CCP
was still
intact).

George