*BSD News Article 85374


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.Hawaii.Edu!ames!enews.sgi.com!news.sgi.com!news.sprintlink.net!news-peer.sprintlink.net!worldnet.att.net!uunet!in3.uu.net!192.220.251.22!netnews.nwnet.net!Symiserver2.symantec.com!news
From: tedm@agora.rdrop.com
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: ahb woes
Date: 21 Dec 1996 08:56:14 GMT
Organization: Symantec Corp.
Lines: 32
Message-ID: <59g8ne$9bs@Symiserver2.symantec.com>
References: <5991ca$87k@Germany.EU.net>
Reply-To: tedm@agora.rdrop.com
NNTP-Posting-Host: shiva3.central.com
X-Newsreader: IBM NewsReader/2 v1.2.5
Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:32903

In <5991ca$87k@Germany.EU.net>, bs@Germany.EU.net (Bernard Steiner) writes:
>
>Hi,
>I am running (ahem.. *was* running, that is) 2.1.5R. Until very recently I
>used an Adaptec 1542c on a 486DX50 VL board with a SCSI-2 disk without any
>problems. Then, I upgraded to an EISA board (with some sort of 486@100)
>and an Adaptec 1740 controlling a wide scsi disk through a wide->narrow
>connector. It's switched to enhanced mode.
>
>

1740's are annoying in the EISA config.  For starters, if you are just trying to slap
in your old disk and expect it to boot, forget it.  The reason is that the 1740
_emulates_ a 1540 in so-called "standard" mode, but in "enhanced" mode the
1740 has nothing to do with the 1540 register set.  Your old disk will need to
have a custom kernel compiled with a 1740 device driver installed for it to
boot.

Also, 1740's are tricky in how they need to be setup in eisa-config.  Here is a 
config that has always worked for me:

Port Enhanced
Interrrupt  Enhanced
DMA  Enhanced.

(keep in mind that the 1740 eisa-config file defines a total of _three_ resources
that have to be set to enhanced for the card to be truly in enhanced mode.  I've
seen a lot of 1740's set up with the port set to enhanced and the dma and
interrupt set to standard.)

Interrupts:  Edge triggered, NOT level-triggered.  Save the level-triggering
for the PCI stuff.