[net.micro.pc] dma on pc

muswiz@sunybcs.UUCP (Steve Levine) (03/15/86)

I am doing digital signal processing with a tms-320-20 card on the
pc.  I have a need to fling blocks of data onto the hard disk while
new audio samples are coming in.  What that means is :

	every 22 microseconds or so (44.1 khz cd format) a 16 bit
	data word will appear in a peripheral card's local ram.  this
	ram can be very big (up to 256k bytes).

	Somehow, I need to shuffle this data from the local ram, out
	to the pc ram (i have a 2 meg talltree ram card in the pc as well)
	eventually, preferably right away, placing the sampled data blocks
	into a contiguous disk file.

	I would like to be able to sample long segments of sound at this 
	sample rate (greater than what can be held in ram) and not have to
	stop the converter.

I figure the problem is one of going around dos calls, possibly writing a
custom assembler routine which tweaks the dma and hard-disk controller, in
order to move blocks of data from memory , directly to the disk.  I know if
the sample-rate was low enough, I could just use dos calls and not miss a
word.

So, does anyone have any knowledge or experience with dma and physical read/
writes of the winchester?   This problem, if solved, opens the way for a lot of
really neat things to happen on the pc (like digital audio storage and other
fun experimental things.).

Anything will help.   Thanks, in advance.

(steve levine alias sunybcs!muswiz)    ihnp4!sunybcs!muswiz