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From: neese@adaptx1.UUCP
Newsgroups: comp.periphs.scsi
Subject: Re: Signals to SCSI Controller
Message-ID: <283400086@adaptx1>
Date: 27 Mar 91 18:59:26 GMT
References: <13730@ccncsu.ColoState.EDU>
Lines: 14
Nf-ID: #R:ccncsu.ColoState.EDU:13730:adaptx1:283400086:000:557
Nf-From: adaptx1.UUCP!neese    Mar 26 09:08:00 1991


>/* ---------- "Signals to SCSI Controller" ---------- */
>I would like to know if an SCSI controller uses the IRQ, DACK, and DRQ lines
>to the computer.  Please forgive me if this is "Common Knowledge" in this
>group (I just joined 2 days ago).

Depends on the SCSI adapter.  IRQ would certainly be used by all, but the
DACK/DRQ lines are only used for DMA.  Bus masters would use these signals,
but PIO cards would not.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex
				uunet!cs.utexas.edu!utacfd!merch!adaptex!neese