[comp.sys.apple] Apple SCSI question...

acct069@carroll1.UUCP (Ron Higgins) (07/22/89)

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References: <1989Jul20.200514.6529@dicome.UUCP.uucp>
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I have a question concerning the Apple SCSI card and a SCSI hard drive on a
//gs.

You have to power up the Hard Drive, then the //gs in order to be able to
access the hard drive.

This is fine for most users, but if you are running a 24 hour BBS system,
you need to have the system come up by itself after a power outtage.

My question is this:  Is there a software call or entry point on the Apple
SCSI card to make it think that the power was just applied?

What I plan on doing is setting the //gs boot slot to 6 and boot off of a
5.25" floppy.  Load ProDOS, Basic.system, and then run a small startup file
that goes into a FOR NEXT loop till the hard drive has come up to speed,
then I'd like to be able to boot my BBS off of the hard drive, but
presently, the system just hangs if I try to access the HD.

Can anyone help?         Thanks,

Ron Higgins

ALBRO@NIEHS.BITNET (07/25/89)

Ron Higgins <marque!carroll1!acct069@CSD4.MILW.WISC.EDU> writes:


>I have a question concerning the Apple SCSI card and a SCSI hard drive on a
>//gs.

>You have to power up the Hard Drive, then the //gs in order to be able to
>access the hard drive.

>This is fine for most users, but if you are running a 24 hour BBS system,
>you need to have the system come up by itself after a power outtage.

>My question is this:  Is there a software call or entry point on the Apple
>SCSI card to make it think that the power was just applied?

>What I plan on doing is setting the //gs boot slot to 6 and boot off of a
>5.25" floppy.  Load ProDOS, Basic.system, and then run a small startup file
>that goes into a FOR NEXT loop till the hard drive has come up to speed,
>then I'd like to be able to boot my BBS off of the hard drive, but
>presently, the system just hangs if I try to access the HD.

I had the same problem for the same reason (running a BBS).  The solution was
to have the power line feed the hard drive directly, but feed the computer
through a 20 amp capacity mechanical relay that switches off on a power
failure, and is delayed from coming back on for 30 seconds after return of
power by a simple 555 timer IC -> triac circuit.  When power returns the hard
drive activates immediately, then 30 seconds later the computer boots from it.

ALBRO@NIEHS.BITNET

acct069@carroll1.UUCP (Ron Higgins) (07/28/89)

Does anyone know if there is a way to have my //gs recognize that I have an
Apple SCSI card and hard drive in slot 7 after I power up the computer and
the hard drive at the same time?

I have to turn on the hard drive and let it come up to speed before I turn
on the computer in order for it to work.  This isn't good because I run a
24hr BBS system and I need to have the system re-boot after a power outage.
I can boot off of a 5.25" disk and have it wait till the hard drive is
ready, but I still can't access the hard drive because I didn't power it up
first.

Can anyone help?

Thanks in advance,
Ron Higgins

dcw@athena.mit.edu (David C. Whitney) (07/28/89)

In article <8907241550.aa12283@SMOKE.BRL.MIL> ALBRO@NIEHS.BITNET writes:
>
>Ron Higgins <marque!carroll1!acct069@CSD4.MILW.WISC.EDU> writes:
>
>
>>I have a question concerning the Apple SCSI card and a SCSI hard drive on a
>>//gs.
>
>>You have to power up the Hard Drive, then the //gs in order to be able to
>>access the hard drive.
>
>>What I plan on doing is setting the //gs boot slot to 6 and boot off of a
>>5.25" floppy.  Load ProDOS, Basic.system, and then run a small startup file
>>that goes into a FOR NEXT loop till the hard drive has come up to speed,
>>then I'd like to be able to boot my BBS off of the hard drive, but
>>presently, the system just hangs if I try to access the HD.
>
>I had the same problem for the same reason (running a BBS).  The solution was

The problem runs deeper than this, though. I've noticed that once the
computer decides that the disk is offline, NOTHING will change its
mind. The only action that DOES work is power cycling the computer.
It's very odd: I usually leave my computer on and just switch off the
drive and monitor. If I fail to turn the drive on before attempting to
access it, I'm doomed. None of the standard tricks of "fooling" the
computer that it was power-cycled work (ie, control-option-OA-RESET,
and then a regular OA-control-RESET). I must actually kill power to
convince the system that the drive is on and ready.

Now, I've asked about this before, but it sort of melted away. Is
there anyone at Apple who a) can produce this odd behaviour and b)
know why it happens and c) has any ideas if it will get fixed (SCSI
rev D???)

Dave Whitney	A junior (well, a senior) in Computer Science at MIT
dcw@athena.mit.edu  ...!bloom-beacon!athena.mit.edu!dcw  dcw@goldilocks.mit.edu
I wrote Z-Link & BinSCII. Send me bug reports. I use a //GS. Send me Tech Info.
"This is MIT. Collect and 3rd party calls will not be accepted at this number."