Radio Shack TRS-80 Model II Reference Manual page 229

Technical Information
DELAY
(function code 6)
This routine provides a delay routine, returning control to the calling
program after the specified time has elapsed.
Entry Conditions
BC
=
Delay Multiplier. IfBC
=
0, then delay time
will
be 426 milli-
seconds. IfBC > 0, then delay time
will
be: 6.5
*
(BC - 1)
+
22
microseconds.
A= 6
RANDOM
(function code 20)
This routine returns a random one-byte value. To extend the cycle of
repetition, the instantaneous time/date are used in generating the number.
You pass the routine a limit value; the value returned is in the range
[O,Hmit-l]. For example, ifthe limit is255, then the value returned
will
be in
the range [0,254].
Entry Conditions
B
=
Limit value
A
=
20
Exit Conditions
C
=
Random number
For B > '1, number returned is in range [O,B -1]
For B
=
°
or 1, number returned
=
°
265