noworol@eecg.toronto.edu (Mark Noworolski) (02/11/89)
I have been trying to interface to a DMA channel in the PC (DMARQ3). Well success has been limited- yesterday I fried my hard disk controller (if anybody has an old 10Meg hard disk controller they want to unload- there's a market here). I have a circuit built (using open collector drivers) which generates DMA requests. I'm programming the DMA chip to do a single transfer and using the IOR pin as an output enable. I only turn it on once I'm in debug (so that nothing is using that channel). Is there something that I should be looking out for? Could there be something else holding the DMA channel? Usually what happens is that midway through my programming of the 8237 the computer crashes with a parity error. Are there any good books/ reference material indicating the proper way to do DMA transfers on the PC (and how to interface into it)? Thanks in advance mark -- There's a really fine line between stupid and clever. Nigel - Lead Guitar, Spinal Tap noworol@ecf.toronto.edu