From the
ABCs of Atari Computers by David Mentley
SPEAKER - The console SPEAKER is controlled by register $D0lF
(53279) decimal. This is the same location as for the console keys. To
start the SPEAKER clicking, POKE in a number between 0 and 7. The continuous
loop
1 POKE 53279,0: GOTO 1
will generate a continuous humming noise. In the XL series, the SPEAKER
noise is routed to the television SPEAKER.
Infrequently Used BASIC Commands
STR$ - In BASIC, the STR$ command converts a number or numeric
variable to a STRing. You will also need a string variable name to place
the string into if you want to use it somewhere else. ONE23$ = STR$(123)
will assign the string "123" to the string variable ONE23$.
VAL - In BASIC, VAL performs the opposite function as STR$.
VAL converts a string which is made of numeric characters to a numerical
variable or value. X=VAL(Y$) will assign the value of 123 to the variable
X if Y$ were a string called "123". If Y$ is an alphabetic character, an
error will result.
From ABCs of Atari Computers by David Mentley (available through the
Antic Catalog in this issue). Reprinted by permission of Datamost, Inc.
ANTIC VOL. 4, NO. 1 / MAY 1985 / PAGE 26