[comp.sys.apple] scsi on 3.5 seagate

AELevy@DOCKMASTER.NCSC.MIL (06/13/89)

I note that I can connect a crate 60m (seagate) and a terminator to my
gs apple scsi card, I can daisy chain a seagate 157n (in a la cie box)
and everything works.  I cannot get the system to recognize the 3.5 157n
by itself (tried with and without terminator).  Will 3.5 inch seagates
not work with the apple scsi??  This is a little wierd and probably has
something to do with the apple scsi card but I do not know (for example
why do you have to terminate drives that work fine on the mac?)

Does anyone know?

Any ideas would be appreciated Thanks Allan

STEIN@UCONNVM.BITNET (Alan Stein) (06/13/89)

>I note that I can connect a crate 60m (seagate) and a terminator to my
>gs apple scsi card, I can daisy chain a seagate 157n (in a la cie box)
>and everything works.  I cannot get the system to recognize the 3.5 157n
>by itself (tried with and without terminator).  Will 3.5 inch seagates
>not work with the apple scsi??  This is a little wierd and probably has
>something to do with the apple scsi card but I do not know (for example
>why do you have to terminate drives that work fine on the mac?)
>
>Does anyone know?
>
>Any ideas would be appreciated Thanks Allan

  Has it been formatted under GS/OS and has the system folder been
put in the root directory?


Alan H. Stein              | stein@uconnvm.bitnet
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shatara@memit.dec.com (Chris Shatara) (06/14/89)

A question regarding Seagate SCSI drives (3.5")....

Do these drives require an EXTERNAL terminator when used with an
//gs (with an Apple SCSI) card or are the terminators on the drive
module?

The reason I ask is that I have a 30meg, 3.5" seagate (ST138N) tied 
to my //gs and I love it.  The "problem" (not really a problem) I have
is that when I'm in an idle state doing nothing, the disk heads sound
like they're seeking.  The light on the drive doesn't come on.  I 
bought the drive for a small outfit in the local area and they told
me this was normal.  I was wondering if I needed to put a terminator on
the cable.  




---
Chris Shatara    shatara@memit.dec.com
		--or-- ...!decwrl!memit.dec.com!shatara
		--or-- shatara%leddev.dec@decwrl.dec.com
---

swong@pro-generic.cts.com (Stanley Wong) (06/14/89)

Network Comment: to #2402 by pnet01!crash!DOCKMASTER.NCSC.MIL!AELevy

> I note that I can connect a crate 60m (seagate) and a terminator to my
> gs apple scsi card, I can daisy chain a seagate 157n (in a la cie box)
> and everything works.  I cannot get the system to recognize the 3.5 157n
> by itself (tried with and without terminator).  Will 3.5 inch seagates
> not work with the apple scsi??  This is a little wierd and probably has
> something to do with the apple scsi card but I do not know (for example
> why do you have to terminate drives that work fine on the mac?)
>
> Does anyone know?
>
> Any ideas would be appreciated Thanks Allan

Well, I have a Mac Crate 60m hard drive on my IIgs.  When I first hooked it up
through my Apple II SCSI card, it wouldn't recognize it.  It knew there was a
SCSI card in the system, but couldn't find any devices.  I called CRATE and
they said that you can get a Terminator that would work from Quality Computers
and that would make the drive work.  I thought this was kind of awkward, since
the ST-277n was already terminated inside.  (underneath the drive).

Anyway, I talked to a friend who has had experience with the Crate drives, and
he told me that there *IS* a difference between pins 25 and 24 on a Mac SCSI
cable and II SCSI.  To make the 25 pin cable working, all I had to do was put
a jumper on the jumper pin just underneath the PC board inside the Crate. 
(The little board which divides the 50 pin cable into 2 25pin ports).

This switched the pins (according to him, and he said he got the info fromt he
SCSI Technical Ref manuals) and would allow me to use the Crate on the GS. 
Well, it worked.

I don't have any specs ont he LaCie, but I suspect that it uses a 25 pin
layout.  I don't know anything about the casing, so there might not be a
jumper pin.  However, If you open the drive, I am sure that you can pull the
50 pin ribbon coming from the Seagate mechanism out from the 25 pin port, and
connect it to at STANDARD 50 pin, terminate it (if necessary) and hook it up. 
I think this would be a possible solution.

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swong@pro-generic.cts.com (Stanley Wong) (06/16/89)

Network Comment: to #2448 by pnet01!crash!decuac.dec.com!mountn.dec.com!memit.dec.com


> A question regarding Seagate SCSI drives (3.5")....

> Do these drives require an EXTERNAL terminator when used with an
> //gs (with an Apple SCSI) card or are the terminators on the drive
> module?

> The reason I ask is that I have a 30meg, 3.5" seagate (ST138N) tied
> to my //gs and I love it.  The "problem" (not really a problem) I have
> is that when I'm in an idle state doing nothing, the disk heads sound
> like they're seeking.  The light on the drive doesn't come on.  I
> bought the drive for a small outfit in the local area and they told
> me this was normal.  I was wondering if I needed to put a terminator on
> the cable.

> ---
> Chris Shatara    shatara@memit.dec.com
>                 --or-- ...!decwrl!memit.dec.com!shatara
>                 --or-- shatara%leddev.dec@decwrl.dec.com
>---

Termination of SCSI devices on the SCSI bus is done to reduce false signals
that can cause your computer system to act erratically.  

Although I find it weird that it only occurs while idling, It wouldn't hurt to
put a terminator on it.  I am sure you could take the terminator back for a
refund if the same results still persist.


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bobl@pro-graphics.UUCP (Bob Lindabury) (06/16/89)

Network Comment: to #76 by pnet01!crash!decuac.dec.com!mountn.dec.com!memit.dec.com

>From what I've been told from some of my associates that HAVE an Apple SCSI
card and homemade hard drive (Seagate), there is a pin that has to be jumpered
that Apple doesn't tell you about in the SCSI manual.  I'm not sure if it is a
jumper or a switch and I'm not sure if it is #8 or #9 but I can find out for
you and post the information here.  I should have an answer for you later
today..I just have to make a quick phone call.  I'll see if there is a file
that I can RCP to people who are interested in it.  If you are, please leave
me e-mail as I will not remember who to send what to if it's not in my
mailbox.  The request for info that is..

Bob

BTW, are you all seeing my signature?  I sure don't see it...