[fpc-pascal] simple sound implementation

Marco van de Voort marcov at stack.nl
Sun Sep 2 19:35:02 CEST 2007

> > Naturally, this is not possible: The PC speaker is simply controlled 
> > by a timer, which creates a square wave (on/off). In ancient DOS times 
> > there was a trick by doing a frequency modulation, i.e. you turn the 
> > timer on and off quite fast. But on Linux etc. the drivers don't 
> > support such cheats.
> <scratches chin> Hmmm... could you use that old Turbo Pascal code to do 
> an inline of the ASM for it? (talking completely through my hat having 
> never attempted such a thing on a linux platform)

Not really. It is not the asm or not, it is simply no hardware access from
programs in principle, one program not being able to lock the entire CPU to
modulate the speaker.

Of course you can, but then you go into the realm of customizing linux.

More information about the fpc-pascal mailing list