d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Update info on SCSI on AlphaStation 500 now that I own one

Browse Source 
to play with and find out myself.
This commit is contained in:
wilko 2002-03-07 20:38:31 +00:00
parent 5e9dfbda74
commit 9abc29b6de
1 changed files with 12 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
release/doc/en_US.ISO8859-1/hardware/alpha/proc-alpha.sgml
View File

@ -1681,8 +1681,18 @@ cpu EV4</programlisting>
<para>Early machines had Fast SCSI interfaces, later ones are Ultra
SCSI capable. AS500 shares its single SCSI bus with internal and external
devices. For a Fast SCSI bus you are limited to 1.8 meters bus
length external to the box. +++ This is what some DEC docs suggest.
Did they ever go UltraSCSI?</para>
length external to the box. The AS500 Qlogic ISP1020A chip can be set
to run in Ultra mode by setting a SRM variable. &os; however follows
the Qlogic chip errata and limits the bus speed to Fast.</para>
<para>Beware of ancient SRM versions on AS500. When you see weird
SCSI speeds being reported by &os; like</para>
<programlisting>cd0 at isp0 bus 0 target 4 lun 0
cd0: &lt;DEC RRD45 DEC 0436&gt; Removable CD-ROM SCSI-2 device
cd0: 250.000MB/s transfers (250.000MHz, offset 12)</programlisting>
<para> it is time to do a SRM console firmware upgrade.</para>
<para>AS600 has one Qlogic SCSI chip dedicated to the internal devices
whereas the other Qlogic SCSI chip is dedicated to external SCSI devices.