On Friday 04 February 2005 13:31, James D. Freels wrote:
>Interesting test. I powered down and disconnected the narrow 50-pin
>cable from card and unplugged
>the power cable from the CD-ROM on the other end. In this
>configuration, there is
>one wide 80-pin cable with 3 hard drives + 1 VXA-1 tape drive on the
>internal connection
>to the card. The new packet-loader is on the external connector.
> Now turn on and reboot.
>
>The Alphabios recognizes the devices correctly, milo boots up, then
>switches to
>the linux kernel to boot up and the system just stops. I repeated
> this several times
>and checked all connections and also tried several available kernel
>choices. Same thing.
>
>Then I powered down, and reconnected the same narrow 50-pin cable
> back to the
>same configuration and now the system boots and behaves just as
> before.
This has the general flavor of the scsi driver hanging while doing the
bus scan because now the terms are really wacko. A more valid test
may be to stick a terminator on the external, connector after
disconnecting the new drive from it, or visiting the cards own bios
extensions, ahh, ... its an alpha, so that may not work either.
In any event all bets are off because the cd had no power, which
*could* leave the bus quite heavily loaded and probably unable to
arrive at enough pullup power to make a logic 1 on any data line.
The cd should be disconnected from the scsi cable entirely for that
test. Puyrchance is it the last device, on the last connector? In
which case it should have the terms turned on and power applied, or
some other means of terminating the cable's end applied to the cable
when its unplugged from the data cable.
>I am wondering now if there is some type of jumper on this pci card
> that enables/disables
>the connectors such that if the internal 50-pin is enabled, it has
> to find a device to
>boot; and perhaps a similar issue with the external connector ?
>
>I mhave been searching the net for a manual on this scsi card and
> cannot seem to find
>one since apparently symbios no longer keeps them for the ncr53c875
>card ?
>
>What scsi card to buy for this Alpha machine ?
>
>On Fri, 2005-02-04 at 11:04 -0500, Gene Heskett wrote:
>> On Friday 04 February 2005 10:12, Geert Uytterhoeven wrote:
>> >On Fri, 4 Feb 2005, James D. Freels wrote:
>> >> The tape drive is within the VXA-2 Packet-Loader 1U rack mount.
>> >> It is connected via an external
>> >> scsi cable that came with the drive. the unit also came with
>> >> it's own terminator which is also plugged into the
>> >> packet loader. The packet-loader is the only device connected
>> >> to the scsi card externaly.
>> >>
>> >> Inside, the scsi card has both a scsi-1 and scsi-2 connector.
>> >> The
>> >
>> >You mean, a narrow and a wide connector?
>> >
>> >> scsi-1 connector has a single device
Questionable choice of terminology, both scsi-1, and scsi-2 are
normally equipt with 50 pin connectors internally, and db-25's or
hi-dens 50 pinners for the external connector. The db-25 is so short
on decent grounds that its been the ruination of many an otherwise
good setup. When you get to wide bus stuff, thats scsi-3, and
possibly even LVD, which isn't compatible with single ended stuff.
>> >> connected (the CD-Rom). The scsi-2 connector has the rest of
>> >> the devices connected on a single cable
>> >> (3 hard drives, 1 VXA-1 Exabyte tape drive). It is a fairly
>> >> long cable, with about 8 inches of cable separating each
>> >> device. The last device on the cable is the VXA-1 tape drive
>> >> followed by a termination on the cable itself.
Ok, a term is on that end of the cable. Are all other devices between
that term and the card completely unterminated? AND is there a wide
to narrow adaptor anyplace in this internal chain?
When testing to see if the cdrom has anything to do with it, the
cdroms cable must be disconnected from the card, which removes the
poorly terminated cdrom (because its powered down too) from the
circuit the only way it should be.
>> >So the cabling is your problem: you should use maximum 2 of the 3
>> > connectors on a SCSI card, since it's supposed to be a single
>> > long chain without branches.
>>
>> Said another way, that card may well have the narrow connector in
>> parallel with the wider one,
most do exactly that FWIW, and some might even term the high order
bits on the card, knowing it will never go offcard in the external
direction. Unforch, you probably can't prove how its setup without
taking that card to a wintel box & gaining access to its own bios
extension preceeding the machines normal boot.
>> and if thats the case, serious term
>> problems are in store. FWIW Geert, all 7 connectors on a given
>> cable can be used, provided the terms are removed from every
>> device but the last one, and the last device is truely on the end
>> of the cable. And the term power supplied is up to specs. The
>> 4.3 to 4.4 volts you get by way of the average cards isolation
>> diode isn't spec by the .6 to .7 volts missing due to that
>> isolation diode.
>>
>> Now, where both the internal connectors on the card and the
>> external connector are in use as this person indicates, then the
>> card, which may have automatic terminations, must terminate ONLY
>> those lines of the wide bus that do not go on out via the rear
>> panel connector to any narrow devices at that end of the cable.
>> The card, as far as the original 8 bit data bus portion of the 50
>> pin cable, effectively becomes a wired or device in the middle of
>> the transmission line and must not terminate those lines. I'm not
>> fam with this card, but most of the cards have an either/or term
>> control, effectively rendering a lashup such as is being described
>> here, pretty much unworkable. My best card was that advansys, and
>> it did not have the ability to terminate just the high order
>> lines, which is what would be required here.
>>
>> I'd recommend strongly that this person get another scsi card, and
>> put the tape drive on it by itself, so that he has all the
>> internal devices on one card, and the external device on the
>> other. Life will be simplified considerably.
>>
>> >It's the same on mine (I have one with internal narrow and wide,
>> > and external wide connectors).
>> >
>> >Gr{oetje,eeting}s,
>> >
>> > Geert
>> >
>> >--
>> >Geert Uytterhoeven -- There's lots of Linux beyond ia32 --
>> > geert AT linux-m68k DOT org
>> >
>> >In personal conversations with technical people, I call myself a
>> > hacker. But when I'm talking to journalists I just say
>> > "programmer" or something like that. -- Linus Torvalds
--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
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Copyright 2005 by Maurice Eugene Heskett, all rights reserved.
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