The speech driver used by PC-VCO does not work as it stands for clock
speeds other than 4.77 Mhz.  This problem can be corrected as follows:

Using debug, change the bytes at offset 2a1 and 2a2 hex in the file SPEECH.COM.
The values for a 4.77 Mhz clock are 08 and 08.	Change the value accordingly:

Value at 2a1   Value at 2a2    Clock speed
------------   ------------    -----------

     8		    8		4.77 Mhz
    0Dh 	   0Dh		8    Mhz
    11h 	   11h		10   Mhz
    14h 	   14h		12   Mhz

The values above are scaled proportionately to the ratio of the desired
clock speed to 4.77 MHz.  For example, 12 Mhz yeilds: 12/4.77*8 => 20.125
which I've taken as 14H.  Experiment will allow you to change the value
according to your particular cpu speed, as well as the ration of clock speeds.
Both bytes should contain the same value (the on/off period for one cycle).

The following example session with debug will change the values:

Enter
copy speech.com speech-8.com<CR>
debug speech-8.com<CR>

where <CR> means the enter key.  Debug will display a "-" prompt.  Then enter

e2a1<CR>.

Debug will display something like "xxxx:02a1  08.".  The xxxx value will
vary from computer to computer.  Debug should display the number 08 as
above.	If this value is not 08, then you do not have the correct SPEECH.COM
(there are several floating around) and should not continue.  This patch only
works for this particular version.

To change the value for an 8Mhz clock, enter

D<CR>

Similarly, enter

e2a2<CR>.
D<CR>

followed by

w<CR>

and then

q<CR>.


The result should appear similar to:

A>debug speech-8.com
-e2a1
xxxx:02a1  08.d
-e2a2
xxxx:02a2  08.d
-w
-q
A>