[comp.os.vms] Custom uVAXII IEQ11-A DMA Needed

JOHNSON%CONDOR@FALCON.BERKELEY.EDU (JOHNSON) (02/12/88)

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	MicroVMS V4.3 QIO's are too slow for our realtime IEEE488 
communications between a uVAX II and a SGI Iris graphics workstation. 
We have an interrupt handler and board driver routines used through 
the CONINTERR driver. We have full machine resources available.
	Further speed is available through the use of the IEQ11's DMA
capability. The physical address of our buffer is required. And, we 
need to allocate and load Qbus mapping registers to our local buffer 
and hold them. Writing a loadable driver just for this purpose is 
an option. Does anybody have a reference for such a driver, physical 
address routines, mapping register selection, 
or know of other options.
	Any help or suggestions would be greatly appreciated.
	I am NOT on the mailing list so replies should be addressed
directly by return mail or ...
				William V. Johnson
				Systems Research Laboratories
				2800 Indian Ripple Road WP197
				Dayton, OH 45440
				(513) 255-8771