cjl@ecsvax.UUCP (Charles Lord) (01/27/88)
I have a question: is it possible to dump info from a port to EMS memory via the DMA channel? I have a DMA-compatable data acquisition board that works OK on the on-board memory on a Wells-American (PC/AT compatable), but leaves garbage in EMS memory at C400:C000 (mapped for DMA at D000:0000). The memory works great for ramdisk and passes diagnostics all day, but i fear that DMA is trying to circumvent a wait state or some such. Any idea/suggestions? The board can also be configured for extended memory. Can the AT really do DMA to the entire 16MB map? The Page Reg appears to be 8-bit, suggest- ing that that is indeed possible. Where is it documented (in read- able form) how to use INT 15 to do those screwy block moves from extended memory to the bottom 640K? Any/all help appreciated! Charles Lord cjl@ecsvax.UUCP ..!decvax!mcnc!ecsvax!cjl