Date   : Wed, 10 Nov 1982 02:54:29 EST (Wed)
From   : Ben Goldfarb <goldfarb.ucf-cs@Udel-Relay>
Subject: Re: CP/M disk logins

The BDOS asks the BIOS to log in a disk by passing a flag in the E register
when calling SELDSK.  As to how the BDOS knows that a log in is necessary,
I can only surmise that the directory checksum is verified before any disk
write, but I have nothing with which to back that up.
                                       Ben Goldfarb