Port 32765 is a write-only port.
Normally the byte at 23388 holds the last value written to the port. Read that, alter your page bits and then write that back to 23388 and to the port.

... it as meaning an absolute value.

Would the rest ...

... /> LD A,(23388) ;Get current value for port (hopefully!)
AND ... /> LD (23388),A ;Put new value back into 23388
LD ... /> OUT (C),A ;Write new value to port
EI

... it as meaning an absolute value.[/quote]

That is ...

Change those two lines with the "OUT" commands into POKE 23388,value : PAUSE 1

You probably don't actually need the pauses in there but just to be sure... :)

What is the recommended way to use cut-off frequencies? Use exactly the lowest and highest frequencies or maybe the lowest - 50 and the highest + 50 or some other value? The latter is probably better since the badly read waves are not excluded so often.

... make sense or have no value.

So I guess ...

... step ahead and gave some "value addition" to this emulator+compilation ...

I saw that with the postage.

All you need to do, is to get a certificate of postage, stamped at the post office, and your item, will be covered up to a value of 27 pounds.

... game has an "objective" technical value or a very fluid animation ...