.\"   $OpenBSD: atzsc.4,v 1.2 1996/10/08 01:20:33 michaels Exp $
.\"
.\" Copyright (c) 1994 Christian E. Hopps
.\" All rights reserved.
.\"
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.\"    notice, this list of conditions and the following disclaimer in the
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.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"      This product includes software developed by Christian E. Hopps.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission
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.\"	$Id: atzsc.4,v 1.2 1996/10/08 01:20:33 michaels Exp $
.\"
.Dd August 31, 1994
.Os
.Dt ATZSC 4 amiga
.Sh NAME
.Nm atzsc
.Nd A2091 low level SCSI interface
.Sh SYNOPSIS
.Cd "atzsc0 at zbus0"
.Sh DESCRIPTION
The
.Tn Amiga
architecture uses a common machine independent scsi sub-system
provided in the kernel source.  The machine independent 
drivers that use this code access the hardware through a
common interface. (see
.Xr scsibus 4 )
This common interface interacts with a machine dependent interface,
such as
.Nm atzsc ,
which then handles the hardware specific issues.
.Pp
The
.Nm 
interface handles things such as DMA and interrupts as well as
actually sending commands, negotiating synchronous or asynchronous
transfers and handling disconnect/reconnect of SCSI targets.
The hardware that 
.Nm
uses is based on the WD33c93 SCSI chip.
.Sh HARDWARE
The
.Nm
interface supports the following Zorro II expansion cards:
.Bl -tag -width "A2091" -offset indent
.It Em A2091
Commodore SCSI adapter, manufacturer\ 514, product\ 2 or product\ 3
.El
.Sh DIAGNOSTICS
.Bl -diag
.It sbicwait TIMEO @%d with asr=x%x csr=x%x
The 33c93 code (sbic) has been waiting too long for a SCSI chip
operation to complete. %d is the line in the source file
.Pa amiga/dev/sbic.c
at which the SCSI chip timed-out.  Asr and csr are status registers
withing the SCSI chip.
.It atzsc%d: abort %s: csr = 0x%02x, asr = 0x%02x
A SCSI operation %s was aborted due to an error.
.It atzsc%d: csr == 0x%02i
A error has occured within the SCSI chip code.
.It atzsc%d: unexpected phase %d in icmd from %d
The target described by
.Sq from %d
has taken the SCSI bus into a phase which is not
expected durring polled IO.
.It atzsc%d: unexpected phase %d in icmd from %d
The target described by
.Sq from %d
has taken the SCSI bus into a phase which is not
expected durring DMA IO setup.
.El
.Sh SEE ALSO
.Xr scsibus 4
.Sh HISTORY
The
.Nm 
interface first appeared in
.Nx 0.9a