On Mon, 9 Apr 2001 jbevren@starbase.globalpc.net wrote: > If you're wanting to do DMA from an ISA card, you can have the DRQ > lines cause an interrupt on the c64, which would react by tristating > the 6522(s) and then asserting DACK. After this, you can use "Pseudo > DMA", which consists of convincing the card that its on a (very slow) > DMA channel by manually toggling the lines to clock data in. Mind > you, ISA's dma doesnt provide the destination address from the > expansion card. It's actually the DMAC's responsibility to do this, > so we dont need to change the address lines. We simply provide ISA > bus signals. *wink* Or you can do it in hardware with a 6844 or 68B44 from Motorola, you should still be able to get them somewhere. Then you can have _real_ DMA at C64 bus speed. - D <david@atari-central.com> http://www.atari-central.com - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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