OpenEuphoria

Re: asm.e questions

• Posted by Kat <KSMiTH at PELL.NET> Oct 24, 1999
• 548 views

----- Original Message -----
From: Everett Williams <rett at GVTC.COM>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Sunday, October 24, 1999 12:21 AM
Subject: Re: asm.e questions


> Nick Metcalfe <metcalfn at ALPHALINK.COM.AU> wrote:
>
> >
> >Unfortunately, I must assume that because the task to be performed is
> >pretty intensive, getting Eu to handle the file operations would
> >probably drink way too much cpu power.  It also means it could not be
> >made totally background and would need some kind of polling loop, the
> >very thing I want to eliminate.
> >
> >Briefly, the isr's file section will need to page large sections of any
> >long waves from disk for mixing and playback in real time.  It will also
> >be used for recording, although this will not be as strenuous, and could
> >probably be done the way you suggest, although I would prefer that to be
> >background as well leaving plenty of cpu power for vu meters, fancy time
> >displays and the like. B-)
> >
> >--
> >  Nick Metcalfe <metcalfn at alphalink.com.au>
> >  http://www.alphalink.com.au/~metcalfn
>
> Nick,
>
> I would like to know what you mean about IO routines eating up too much
CPU.
> I don't know how efficient Eu's file routines are, but IO typically is
more
> a consumer of clock time than CPU cycles. Finding ways to make IO
efficient
> on any particular configuration is no simple job, but CPU cycles are not
> usually the most prominent concern. Also, from what I can tell, all Eu
> driven file IO is synchronous...meaning Eu waits on the completion of IO
to
> proceed to the next instruction. Buffering and caching external to Eu can
> improve the efficiency of such IO, but if the CPU has nothing else to do
> other than wait on the IO, much will go to waste. Even if you do all the
IO
> in the background through some asm routine, you will still have to write
> some polling routine to tie the IO to the Eu code. I think that you said
> that this was to be done in DOS, where you have no call back ability. I
> don't see how you will get to what you want to do without moving to a
> Windows type setup.

Maybe you can call DMA routines if your motherbd supports such things, and
call the DMA *before* you need the data, so it's ready when you are. Maybe?

Kat