1.\" $NetBSD: wdsc.4,v 1.6 2017/02/17 22:24:47 christos Exp $ 2.\" 3.\" Copyright (c) 1999 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Steve C. Woodford. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd February 17, 2017 31.Dt WDSC 4 mvme68k 32.Os 33.Sh NAME 34.Nm wdsc 35.Nd Western Digital WD33c93 SCSI Bus Interface Controller 36.Sh SYNOPSIS 37.Cd "wdsc0 at pcc? ipl 2" 38.Sh DESCRIPTION 39The 40.Nm 41driver provides an abstraction layer between the SCSI hardware 42fitted to the 43.Tn Motorola 44MVME147 single board computer (WD33C93), and the machine 45independent SCSI drivers described in 46.Xr scsibus 4 . 47.Pp 48In addition to sending the required SCSI commands to 49target devices on the SCSI bus, the 50.Nm 51driver deals with DMA, device interrupts, sync/async negotiation 52and target disconnects/reconnects. 53.Sh DIAGNOSTICS 54Too many to mention. 55.Sh SEE ALSO 56.Xr mvme68k/pcc 4 , 57.Xr scsibus 4 58.Sh BUGS 59Negotiation of Synchronous SCSI data transfers has been 60deliberately disabled in the MVME147's 61.Nm 62driver as it has proved extremely difficult to make it 63work reliably in this mode. 64.Pp 65The 66.Nm 67driver does not respond well to exceptional conditions 68caused by poor SCSI cabling and/or termination. In those 69instances the machine is likely to require a hard reset 70to recover. 71.Pp 72The current 73.Nm 74driver should be blown away and replaced with a machine independent 75version. 76