Re: How to debug inside the BIOS and/or interrupt?

On Jul 5, 7:15 am, NoS...@[EMAIL PROTECTED]
 (Bob Masta) wrote:
> I don't have an answer to your problem, but I am curious about
> your statement that the interrupt handler is told to "do nothing"
> until data is again available.   SB data is normally transferred via
> DMA (except for a crappy old 8-bit mode), and the interrupt is
> just to tell you that the DMA block is done.   I don't recall how
> the SB interacts with the DMA if you don't acknowledge the
> interrupt to the SB... it might stall, or it might just loop on the
> old contents of the DMA buffer.  Is it possible that the
> "do nothing" is causing the SB and the motherboard DMA
> controller to get out of sync somehow?  Still, I wouldn't
> think this would lock up, just output garbage data to the SB.

I apologize; I misrepresented what the handler does when it is told to
"do nothing".  I have a flag in memory that the interrupt handler
checks on entrance.  If it's set "enabled", the handler updates the
video and audio buffers.  If set "disabled", the handler fills the
audio buffers with silence.  Either way, it isn't actually disabled,
but "told" to do a "NOP"-type of loop.  This type of control is
necessary so that the main program code can "pause" the interrupt
handler's functions if the data queue becomes empty and needs time to
fill up again.