Date   : Thu, 10 Jul 1986 21:26:25 EDT
From   : "Robert L. Plouffe" <PLOUFF%MX.LCS.MIT.EDU@mit-mc.ARPA>
Subject: [PLOUFF%MX.LCS.MIT.EDU: LE, SPERRY, CLK UTLS]

Date: Sun,  6 Jul 86 12:05:14 EDT
From: Robert L. Plouffe <PLOUFF%MX.LCS.MIT.EDU at MIT-MC.ARPA>
To:   INFO-MICRO%MX.LCS.MIT.EDU at MIT-MC.ARPA,
      INFO-CPM%MX.LCS.MIT.EDU at MIT-MC.ARPA,
      info-ibmpc at USC-ISIB.ARPA
cc:   PLOUFF%MX.LCS.MIT.EDU at MIT-MC.ARPA
Re:   LE, SPERRY, CLK UTLS

The file EDGCLK.ARC has been uploaded to SIMTEL20 and located
in PD:<MSDOS.COMPATIBLES>EDGCLK.ARC.

This ARC file contains the source and executable files for two
utilities that will be useful to owners of Leading Edge, Model M
and Sperry PC personal computers. (Maybe Model D also. See below.)
They are:

       LE_MCLK   Reads the on-board battery backed-up clock
                 and sets the current clock to its values.
                 This code is intended to be executed in your
                 AUTOEXEC.BAT file.  The .COM file is only 28 bytes.

       SETCLK    Sets the date and time of the battery backed-up
                 clock and simultaneously updates the current clock.

The function of LE_MCLK is built into DOS 2.11 as supplied with
the machine, and the v2.11 COMMAND.COM will update the battery
clock with the internal DATE and TIME commands.  So, if you stick
with DOS 2.11 you don't need these utilities.  However if you
upgrade your DOS to 3.xx, you will find that it has no knowledge
of the on-board battery backed-up clock.  These utilities will then
do the job and restore full function to the use of the battery clock.

The programs use an undocumented feature of the on-board
ROM BIOS. The Time-of Day interrupt (INT 1AH) has four additional
functions beyond that of the IBMPC ROM BIOS. This is fully explained
in the documentation.

I suspect that the DOS 2.11 supplied with the Leading Edge, Model D
is identical to the one supplied with the Model M.  If so, then the
ROM BIOS must also provide the same functionality for the additional
INT 1AH functions  - so this code will probably work with a model D
also.   Someone who has a Model D please let me know.  Reply to
PLOUFF at MIT-MX since I am not on all of the mailing lists to which
this is directed.