Re: Sound in Integer BASIC

["Michael J. Mahon" <mjmahon@aol.com>]

Jim wrote:
> I've got a small programme that just takes input from the serial port and
> displays it on the screen. It includes a POKE to click the speaker for each
> character displayed, and this works quite well. However, the standard POKE
> (which I don't have on me at the moment) is perhaps a little harsh,
> especially if there's a lot being displayed.

Unless Integer BASIC implements POKE without an indexed store, you
should use X=PEEK(loc) to toggle the speaker.

The indexed store accesses the speaker toggle *twice*, generating
a very short pulse, rather than changing the state as you wish.

As Matt pointed out, the ~8-instruction routine to generate a tone
is a very good beginning machine language exercise:  toggle, delay,
loop til done.  If the delay and duration are set by free page zero 
locations (like $06 and $07 for Applesoft) you can POKE them to vary
the beep prior to the CALL.

-michael

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