Date: Thu, 15 Feb 1996 17:40:57 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Malcolm Taylor <malcolm AT manawatu DOT gen DOT nz>
Cc: djgpp AT delorie DOT com
Subject: Re: how to allocate DMA pages ?


On Thu, 15 Feb 1996, Malcolm Taylor wrote:

> There is actually an easier method than that (it has it's restrictions
> though). Under DPMI the first 1M of memory is always locked and has
> the linear addresses 0-1M. Just allocate some DOS memory from the DPMI
> provider and the get the linear address by segment*16+offset. This can

Another method is to use the VDS (Virtual DMA Services) API, which is 
supported by every memory manager I know of.  These are just a few 
functions of interrupt 4Bh (if memory serves); look them up in the 
Interrupt List.  The nasty problems of mapping physical to virtual 
addresses should be dealt with by using that API.