

		DECtalk PC and SCSI II/CD ROM Readers.

We have found that there might be a time when your SCSI II adapter and/or
CD ROM Reader and will not work when a DECtalk PC is installed. The problem 
accures when the DECtalk PC is at a I/O adress used by the SCSI II adapter.
If the adapter driver finds a DECtalk PC at an I/O address it wants to use,
it may hang the system.  Additionally the utility DT_CONF.EXE trys to find 
and initialize any DECTALK PC modules at the following I/O base addresses: 
240, 250, 340 and 350. If the adapter for the CD ROM Reader also uses one of
these I/O base addresses for a "mailbox", DECtalk's DT_CONF.EXE utility will
try to query it an it will no longer work.

In order to work around this conflict we have added switches to the DT_CONF
and DT_DRIV commands which cause the DECtalk to be initialized only at a 
single otherwise unused I/O address.

If you find you are having a problem getting your system to boot or 
accessing your CD ROM Reader after installing the DECtalk PC, power down 
your PC and remove the DECtalk. Reboot your system to insure that it boots 
up satisfactorily and check the CDs operatin to insure that it is the
DECtalk PC causing the problem.

If it is, you will need to change the switch settings on your DECtalk to
correspond to the I/O address you want to use.  There isn't any hard and 
fast rule as to which address is open in your PC.  If you have a 
SoundBlaster 16 card with a SCSI II interface card in your PC, address 250
has worked.  The I/O adresses used depends on what SCSI adapter you are
using, e.g. Adaptek, Trantor, Ultrastor, etc, or your CD ROM Reader may come
with its own adapter card or your sound card may have an adapter built-in.

Determining which I/O addresses are used by the various devices in your PC
can be a challenge.  A proposed procedure for finding out which ones are
used is as follows:

1. Many devices when they install their drivers at boot up will report
on the screen what I/O address they are using.  This information will
usually scroll by too quickly to be read.  MS-DOS V6.x provides the
capability to individually run each command line in the PC's CONFIG.SYS
and AUTOEXEC.BAT files at startup.

To utilize this feature reboot your system.  When the "Starting MS-DOS..."
message appears on the screen, quickly press the F8 key.  You will be 
prompted before each line in the files before they are executed.  Press the
"Y" key when you are prompted with a new line.  After the line has been
executed you will normally be given information back as a result of 
executing that line.  The ones to particularly observe are the commands 
which are the drivers for adapters/options which are installed in your PC.
When these drivers are initiated they will report back as to what system
resoures they are using such as COM/LPT ports, IRQs and I/O addresses.  Take
note as to which I/O address are being used.  For instance a Sound Blaster
16 with a SCSI II interface adapter for a CD ROM could utilize I/O address
240 for the sound card and 340 for the SCSI II interface.  In this 
particular case we found that we could also not use I/O address 350 even
though we could not determine if any device was using it.  The reason for 
this is that the sound card uses 340 and part of 350.

2. Select the first I/O adress that does not seem to be used by any 
other device.  In the example above, we selected I/O address 250 because
it seemed to be the best candidate.  To have the DECtalk only use this I/O
address during system boot we needed to add "switches" to command lines
in two files.  You do this by editin the DT.bat file in the DECtalk's file
directory (the default directory is DECTALK) and both the CONFIG.SYS and
AUTOEXEC.BAT files in the system root directory (usually c:\).  On the lines
that say DT_CONF and DT_DRIV -C, add the -b xxx switch where xxx is the 
selected base I/O address.  For example, in the case we have been describing
where we have selected I/O address 250, the command lines would look like:

	DT_CONF 
	Dt_DRIV -C -B 250

Save the files after you have edited them.

3. You will also need to set the selected I/O address on the DECtalk PC
board.  Locate teh switch pack on the board and set the swiches accordingly.
The Install/User Guide describes how to set the switches and what are the 
available switch settings.  In the case described, I/O address 250 was set
by setting switch 6 to ON and all the rest to OFF.  You should now turn off 
your PC and reinstall the DECtalk PC making sure that the speaker is plugged
in.  Restart the computer and repeat teh line-by-line boot process described
above.  Observe the same driver load lines as before and be sure that each
appears to load satisfactorily.  If a particular device doesn't appear to
load satisfactorily or the system stops when you try to run a line, then 
their is probably still a conflict between the device's settings and the
DECtalk's.

4. Referring to the device's installatin manual may provide information
as to the I/O address it uses as defaults and what other addresses can be
set.  Try changing the device's I/O address to one not available on the
DECtalk and not used by another device.

5. Repeat this process until you get a satisfactory system startup and the
DECtalk speaks its startup message and you can access the CD ROMs directory.


MULTIPLE DECTALK PC BOARDS.

If you are running more than one DECtalk PC card in your system your 
DT.BAT and AUTOEXEC.BAT file(s) should include the base address of each 
card.  For cards that are set at I/O addresses 240 and 350 the command
lines would look like:

	DT_CONF  
	DT_DRIV -c -B 240 -c -b 350

