Udo van den Heuvel wrote in a message to Thomas Seeling:

 UvdH>> Where can I find info on how to use the DMA chips of my PC (with
 UvdH>> e.g. VP)? Please help!

 TS> You don't want to do this in application programs for OS/2.

 UvdH> But I need to!
 UvdH> Or can I do polled I/O (180+K/s) and save the incoming data
 UvdH> to a (SCSI) HD without losing a bit?

Let's step back a minute.  Exactly what is it that you are trying to do,
and what are the time constraints?  Polled I/O is actually FASTER than DMA
through the motherboard controller, which is non-bus-mastering DMA,
provided that you don't pull an IRQ on every byte or something similarly
foolish as is needed with the serial port.  But you can maintain data
transfer at a pretty good clip using IRQ-and-buffer techniques to do polled
I/O with neither DMA nor even a memory aperture, as the NE2000-style
Ethernet card proves.

If you need to hook an IRQ, do DMA, or meet critical time constraints, then
you will need a device driver under OS/2.
 
-- Mike


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