1.\" 2.\" Copyright (c) 1995, 1996 3.\" Justin T. Gibbs. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. The name of the author may not be used to endorse or promote products 14.\" derived from this software withough specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" 27.\" 28.Dd April 20, 1996 29.Dt AHC 4 i386 30.Os FreeBSD 31.Sh NAME 32.Nm ahc 33.Nd Adaptec VL/EISA/PCI SCSI host adapter driver 34.Sh SYNOPSIS 35For one or more VL/EISA cards: 36.Cd controller eisa0 37.Cd controller ahc0 38.Pp 39For one or more PCI cards: 40.Cd controller pci0 41.Cd controller ahc0 42.Pp 43To enable tagged queueing: 44.Cd options AHC_TAGENABLE 45.Pp 46To enable SCB paging: 47.Cd options AHC_SCBPAGING_ENABLE 48.Pp 49For one or more SCSI busses: 50.Cd controller scbus0 at ahc0 51.Sh DESCRIPTION 52This driver provides access to the 53.Tn SCSI 54bus connected to an Adaptec 55274x, 284x, 2940, 3940, or controllers based on the 56.Tn AIC7770, 57.Tn AIC7850, 58.Tn AIC7860, 59.Tn AIC7870, 60or 61.Tn AIC7880 62host adapter chips. 63Features include support for twin and wide busses, 64ultra 65.Tn SCSI, 66two active commands at a time per non-tagged queueing target, 67tagged queuing, 68and SCB paging which allows up to 255 active commands on all adapters 69except those using 70.Tn AIC7770 71chips prior to revision E. 72Tagged queueing is enabled with the 73.Dq Dv AHC_TAGENABLE 74configuration option. 75SCB paging is enabled with the 76.Dq Dv AHC_SCBPAGING_ENABLE 77configuration option. 78.Pp 79Per target configuration performed in the 80.Tn SCSI-Select 81menu, accesible at boot 82in 83.No non- Ns Tn EISA 84models or through an 85.Tn EISA 86configuration utility for 87.Tn EISA 88models, 89is honored by this driver with the stipulation that the 90.Tn BIOS 91must be enabled for 92.Tn EISA 93adaptors. This includes synchronous/asynchronous transfers, 94maximum synchronous negotiation rate, 95disconnection, 96and the host adapter's SCSI ID. 97.Pp 98Note that I/O addresses are determined automatically by the probe routines, 99but care should be taken when using a 284x 100.Pq Tn VESA No local bus controller 101in an 102.Tn EISA 103system. Ensure that the jumpers setting the I/O area for the 284x match the 104.Tn EISA 105slot into which the card is inserted to prevent conflicts with other 106.Tn EISA 107cards. 108.Sh BUGS 109Some Quantum drives (at least the Empire 2100 and 1080s) will not run on an 110.Tn AIC7870 111Rev B in synchronous mode at 10MHz. Controllers with this problem have a 11242 MHz clock crystal on them and run slightly above 10MHz, causing the 113drive much confusion. Setting a maximum synchronous negotiation rate of 8MHz 114in the 115.Tn SCSI-Select 116utility 117will allow normal function. 118.Pp 119The code to perform SCB paging doesn't work properly, don't use this option 120at this time. 121.Sh SEE ALSO 122.Xr aha 4 , 123.Xr ahb 4 , 124.Xr cd 4 , 125.Xr scsi 4 , 126.Xr sd 4 , 127.Xr st 4 128.Sh AUTHOR 129The 130.Nm 131driver was written by Justin Gibbs. The 132.Tn AIC7xxx 133sequencer-code assembler was 134written by John Aycock. 135.Sh HISTORY 136The 137.Nm 138driver appeared in 139.Fx 2.1 . 140