[comp.sys.mac.misc] Hard disk goes away and returns

cudat@warwick.ac.uk (J M Hicks) (11/02/90)

About a week ago I submitted the following item of news:-

>I (perhaps foolishly) tried to start a Mac IIcx with an old startup floppy
>disc
>(probably intended for a Mac+).  The computer wouldn't start and wouldn't
>eject the disc.  Eventually I poked a wire
>into the hole next to the disc drive to eject
>the disc.  (I have since discovered that I could probably have ejected
>the disc by holding the mouse button down when turning the computer on.)

>After this, the computer behaved as if its hard disc were not there.
>Turning it on gave an icon of a floppy disc with a flashing
>question mark. Using a proper startup disc (Apple's System Tools disc) gave
>a display without the hard disc icon.

>The following day I selected "Apple HD SC setup"
>on the Apple System Tools disc. It seemed to
>know the name of the hard disc.  I selected "Test" and the hard
>disc was tested without any trouble.  The next time I turned the
>computer on, it used the hard disc as the startup disc
>without any trouble.

I received several replies, which appear below.  It seems that I may
have altered the PRAM and trying the HD SC setup corrected this.
I reset the PRAM as suggested below.  It had no noticeable effect
but it has made me feel happier.

Many thanks to everyone who replied.

-----
Date: Fri, 26 Oct 90 14:25:33 +0100
From: Michael Yue <estgwbg@uk.ac.warwick.cu>

I've read the news about your mac. I had that problem once. I have a SE/30 and
a removable HD on the SCSI port. The internal HD is the startup device. If
I don't turn the removable on, my mac gives a sad mac because It can't find
something - which I don't know. But if I leave the mac - whith the sad mac
- on and turn the removable on, it will boot from the removable rather than
from the internal. In order to boot from the internal, I have to turn the
removable on and let it mounted the disk befor I can turn the Mac on. Strange
and bizarre. By the way, I am running 6.0.2 and multifinder with lots of inits
and cdev.

Mike
-----
Date: Mon, 29 Oct 90 10:21:11 PST
From: dplatt@com.coherent
Sender: dplatt%coherent%uucp.mcsun@net.eu.mcsun

I'd guess that your use of an outdated boot floppy might have corrupted
the IIcx's nonvolatile parameter RAM.  A misconfigured RAM can cause the
Mac to try persistently to boot from a device that isn't present, and
ignore the rest of the devices on the bus;  it might also be capable of
causing the machine to completely ignore the SCSI bus.

Running the HD SC Setup may have corrected the PRAM corruption.

Dave Platt                                             VOICE: (415) 493-8805
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-----
Date: Sun, 28 Oct 90 23:59:19 -0500
From: Pascal Gosselin <pascal@org.cam>
Sender: pascal%uucp.altitude@edu.mcgill.mcrcim.larry

Could be a QUANTUM Hard Disk with the sticky lubricant...  Have the
HD serial number checked by a dealer, the upgrade is free if that is
the case.

you might also want to reset the PRAM by doing a command-option-shift
and selecting the control panel.  This will reset the scsi startup info.

| Pascal Gosselin          | Internet: Pascal@cam.org   Applelink: CDA0585   |
| Gest-Mac Inc. Apple VAR  |   Voice (514) 767-4444   Fax (514) 767-7337     |
-----
Date: Fri, 26 Oct 90 15:59:14 +0100
Sender: weigele%de.uni-hamburg.informatik.bosun2@net.eu.mcsun

Well, as far as I know there is some internally saved variable
that determines the startup disk. You may change it through the
Special Menu ("define startup" or the like), in connection with
the disk icon active the moment you choose this menu. I suppose the
old system disk changed it from HD to internal drive.
The setting is not used when inserting a
disk to boot from the internal drive anyway.

Martin Weigele, FB Informatik, Univ. Hamburg, Bodenstedtstr. 16,
D-2000 Hamburg 50, GERMANY.
-----

--
J. M. Hicks (a.k.a. Hilary),
Computing Services, Warwick University, Coventry, England. CV4 7AL
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