S3 Help 2.5
-----------

To install this new HELP software into S3, a new Library ROM needs to
be created.  This procedure is described below:

1. Download S3HELP25.HEX to S3 in the normal way.  S3HELP25.HEX is an
Intel Hex file.  The data will reside between addresses E000-FFFFH.

2. Do a RAM checksum (CKSUM key) from E000 to FFFF:

>CHECKSUM E000,FFFF

or

>CH E000,FFFF

The resulting SUM should be: 0D0D1A

3. BURN a (blank) 2764 or 27C64 from E000-FFFFH:

>BURN 2764-INT
12.5V TO PIN 1
SECTOR 07=E000,FFFF

4. Do a ROM checksum (F3).  The SUM should be the same as the RAM
checksum above.

5. With the freshly BURNt HELP ROM in S3's ZIF socket, press HELP, and
then ENTER.  The HELP program will now load, and S3 should the display
the following sign-on message:

DATAMAN S3 HELP 2.5
>

"But my S3 has lost it's HELP - I can't BURN a 2764"
----------------------------------------------------

There is another method of installing a HELP ROM into S3, which doesn't
involve actually BURNing an EPROM, which makes use of an undocumented S3
command, and is described below:

A. Download S3HELP25.HEX into S3, and perform a checksum of RAM, as
described in sections 1 & 2 respectively.

B. Press ESC, and an asterisk should appear.  Now press HELP.  S3 should
display the following:

*UH XXXX,XXXX

This command is called User to Help.  It transfers data from USER RAM
into the HELP RAM.  There are three blocks of code which need to be
transferred to the USER RAM.  The HELP code can't be transferred in one
go, as reserved areas of HELP RAM would be corrupted, and S3 would
crash.  The addresses of these blocks are as follows:

        1. E000-FD4F
        2. FE50-FEFF
        3. FF02-FFFF

Enter the first set of addresses, and press ENTER.  Now press ESC-HELP
and enter the second set.  Do the same with the third set.  S3's screen
should look as follows:

*UH E000,FD4F
*UH FE50,FEFF
*UH FF02,FFFF

You will notice that the prompt symbol ">" doesn't appear after entering
the third set of addresses.

C. Now switch S3 OFF and then back ON, and the HELP ROM should introduce
itself thus:

DATAMAN S3 HELP 2.5
>

If this message doesn't appear, or S3 crashes, the S3HELP25.HEX file
probably wasn't downloaded correctly, or the incorrect addresses were
entered in the UH command.

If you experience any difficulties installing your HELP ROM, please call
Dataman's Technical Support department.

Dataman Programmers Ltd
Station Road
Maiden Newton
Dorchester
Dorset
DT2 0AE
United Kingdom

Tel: +44/0 1300 320719
Fax: +44/0 1300 321012
BBS: +44/0 1300 321095
email: info@dataman.com

GPC 15th March 1995 Dataman Programmers Ltd E&OE
