   This file describes how to use the EQCREATE.BAS BASIC program to create
a new equalization file using a mathematical formula, or to re-make one of
the EQ files supplied on the Test and Utilities disk to optimize for speed,
accuracy, or frequency range.

First make sure you have a copy of BASICA on a disk or in the DOS path,
and the EQCREATE files from the SYSTEM ONE TESTS and UTILITIES disk.

The easiest way to use eqcreate is to start from DOS, then enter

          EQCREATE

which runs the following eqcreate.bat batch file 

          BASICA EQCREATE
          S1 EQC

Another way to use eqcreate from DOS is

          S1 EQCREATE /r112

A third way is to enter the following commands from the main menu in S1
(assuming it was called as S1 /r112)

          Load Procedure EQCREATE
          Run Procedure

   If necessary, use the XDOS command and CD\directory to change to the
directory that contains the procedure EQCREATE, and EXIT to return to S1.

Any of these should load and run the BASIC program EQCREATE.BAS, which
shows a list of choices for several equalization curves including 
single pole de-emphasis, RIAA (with or without the IEC amendment),
and a choice for a user entered formula.

If these choices do not appear, DOS may not be able to find BASICA
or there may not be enough memory available for both S1 and BASICA.
You may use the XDOS command from S1 to check for these possibilities.
If there is not enough memory to run BASICA from S1, try the /r option when
loading S1 to reserve more memory, or quit S1 and run the EQCREATE batch file.

   If some other formula is desired, you may modify the EQCREATE BASIC program.
Put your formula in the subroutine at the end of EQCREATE.BAS by replacing
the example formula (V=1000/W) that is already there at line 500.
To edit the Basic program, hold the <Ctrl> key while pressing the <Break> key.
The screen should show "OK".
To make sure nobody has re-numbered the program, type LIST 500.
The screen should show "500 V=1000/W".
To replace the example formula with your formula, type
500 followed by your formula to set V, and then the <Enter> key. 

Note: You may use any of the following pre-calculated variables:
          F is frequency in Hertz
          W is angular frequency in radians / seconds.
          X is angular frequency SQUARED in rad * rad / sec / sec.

Then type RUN to start the EQCREATE program again.

   Enter the number corresponding to the type of equalization curve you want,
followed by pressing the <Enter> key. Likewise enter the number of points to
be generated and the start and stop frequencies. It is recommended to start
at a high frequency and end at a low frequency to match the direction of the
test that will be using this equalization curve.
   The program will list the values as it calculates them. If you wish to
change something, press any key other than Enter and then the <Enter> key.
If all looks well, then press the <Enter> key and BASIC will return control
to the EQCREATE procedure.
   The procedure will ask you to enter the frequency at which you wish
no attenuation nor gain. This is set by Util Normalize.
   The procedure will display the normalized curve. Press <Enter>.
   Then give the procedure the name of a file for storing the eq curve.
   If you wish to have a pre-emphasis curve instead of de-emphasis, use the
Util Invert command and then Save Eq again.
