Date: Mon, 28 Sep 1998 10:08:45 -0600 From: Steve Passe <smp@csn.net> To: "Justin T. Gibbs" <gibbs@narnia.plutotech.com> Cc: scsi@FreeBSD.ORG Subject: p2b scsi termination Message-ID: <199809281608.KAA12061@Ilsa.StevesCafe.com>
next in thread | raw e-mail | index | archive | help
Justin,
I have been running an asus p2b-ds with -current for a week now, VERY
nice board! Am totally confused about the scsi term issue. Kevin @ atipa
said you worked out some of the details on this.
1: the manual states: "The 68-pin WIDE SCSI connectoris always terminated
and will only work as an end device"
is that really true?
2: I want to put a wide device on the 68-pin wide (not u2w) bus, and
several narrow devices on the 50-pin bus. The BIOS doesn't have
the usual choice of "low off/hi on", only "off/on". If I turn the
SE term off, will it implicitly leave the 'high' side on? Or is this
even possible? The adaptec datasheet for the aha2940u2w board claims
that all connectors can be used simultaniously, so I think it should
work...
3: Am I correct in believing that the uw bus and narrow bus are
effectively ONE SCSI bus, with the hi 8-bits left off one half?
(u2w TERM ON) (SE TERM OFF, implicit hi-byte ON?)
|u2w conn| |uw conn|====-----|narrow conn|
---------- --------- -------------
|| || |
||={da0} ||={da3} |-{st0}
|| || |
||={da1} || |-{cd0}
|| || |
||={da2} || |-{da5(zip)}
|| || |
||={TERM} ||={TERM} |-{TERM}
4: Kevin postulated that the BIOS actually enables/disables AUTOMATIC
TERMination, so that it should always be left on, and the hardware
will determine whats where, is that possible? This worrys me as
I have had "automatic TERMination" fail to work properly on other
MBs in the past, requiring a manual setting to function properly.
tia,
--
Steve Passe | powered by
smp@csn.net | Symmetric MultiProcessor FreeBSD
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-scsi" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199809281608.KAA12061>