OEM Manual Adaption

4. Additional Statements

The following statements are non-standard statements found in some previous versions of BASIC. A particular implementation may support these statements and functions:

NOISE Statement

Purpose:

Generates noice through an external speaker.

Syntax:

NOISE source, volume, duration

Comments:

The noise source is a numeric expression in the range 0 to 7. This parameter indicates gradations of noise from 'periodic' (0 to 3) to 'white' (4 to 7).

If you want to use a noise source of 3 or 7, the frequency of voice 3 is used instead of the system clock. You can set the voice 3 frequency with the PLAY or SOUND statements. The volume is a numeric expression in the range 0 to 15.

The duration is measured in clock ticks, with 18.2 ticks equal to one second. The duration must be a numeric expression in the range 0 to 65535.

Sound produced by the NOISE statement goes to the external speaker. A SOUND ON statement must be executed before using NOISE, or an 'Illegal function call' error will be generated.

Example:

This example illustrates all the possible noice sources from 0 to 7. Note the use of three voices in the PLAY statement.

SOUND ON
FOR N = 0 TO 7
   NOISE N, 15, 250
   PLAY "", "", "V0"
   FOR I = 1 TO 6
      PLAY "", "", "V15;0=" + VARPTR$(I) + "  ;CDEF"
   NEXT I
NEXT N