Path: utzoo!attcan!uunet!seismo!sundc!newstop!sun-barr!decwrl!ucbvax!NIEHS.BITNET!ALBRO
From: ALBRO@NIEHS.BITNET
Newsgroups: comp.sys.apple
Subject: RE: Apple SCSI question...
Message-ID: <8907241550.aa12283@SMOKE.BRL.MIL>
Date: 24 Jul 89 18:30:00 GMT
Sender: usenet@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 30


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