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From: juan@bitnerd
Newsgroups: comp.sys.next
Subject: Re: PLI Superfloppy vs. CubeFloppy (DIT) & Floppyworks; NeXTConnection
Message-ID: <1991May9.165912.1042@bitnerd.uucp>
Date: 9 May 91 16:59:12 GMT
References: <1991May9.131840.11866@engage.enet.dec.com>
Sender: juan@bitnerd.uucp (Juan Pineda)
Reply-To: apple.com!bitnerd!juan (Juan Pineda)
Organization: Apple Computer Inc.
Lines: 64

In article <1991May9.131840.11866@engage.enet.dec.com> tenny@ootool.dec.com  
(Dave Tenny) writes about difficulty booting when he's got a floppy drive  
connected to his cube:

> ... Anyway, the default (#3) for the floppy drive works, MOST OF THE TIME.
> There is no on/off switch, so I just leave it plugged in all the time.
> Here's the problem:  the machine only boots about 50% of the time.
> Sometimes it boots without a hitch.  Other times it stops.  
> If I have the verbose ROM Monitor enabled, I see these messages like...

I've experienced similar difficulties.   I have a 660MB cube that was upgraded  
from a 68030 and a PLI supperfloppy.  After I connected to floppy, my system  
would not boot at all.

Enabling the monitor verbose mode resulted in similar messages to the ones Dave  
reports when the system was powered up.  Looking at the messages, it was clear  
that the system was trying to boot from the floppy instead of the hard drive.   
If at this point, I broke back to monitor mode (<command><command>tilde), and  
issued a "b sd" command to reboot the machine, it would boot just fine.

Here is what I think is going on.  The hard drive on my machine takes about 15  
seconds to spin up.  It's a loud drive (an HP full height) so I can easily hear  
the heads going through the initialization procedure.  On power up, the ROM  
monitor looks around for SCSI devices, and sees the floppy, but since the hard  
drive is not yet powered up, it does not see the hard drive.

I would expect that NeXT would have put some hooks in the code for this case,  
like waiting for a fixed period of time on power up, but apparently, it does  
not catch all cases.  Perhaps the HP drive has a longer power up time than  
other controllers.  Since this is a timing problem, I would expect that the  
problem would depend on the particular combination of drives in your  
configuration.  In Dave's case, perhaps the Cubefloppy and his hard drive take  
about the same time to power up, and that is why his system boots  
intermittently.

Here's a work around that I've been using.

1) Normally the monitor "boot command" parameter in the ROM monitor is set to  
boot from the hard drive.  Change the "boot command" command to be blank, so  
that on power up it does not try to immediately boot from SCSI.  Do this with  
the p command in the ROM monitor.

2) Enable verbose mode in the ROM monitor with the P command.

3) Steps 1 & 2 need be performed only once, since these changes are stored in  
the ROM.  Power down the system.

4) Now every time you power up the system, it will break to the ROM monitor,  
since the boot command is blank.  Wait until your hard disk is ready.  I can  
hear mine, you may have to experiment, and time the delay, if yours is not as  
loud.  At the ROM prompt, type "b sd" to boot from the hard drive.  It should  
boot just fine.

Note that in verbose mode, you see the PLI floppy waiting for about 15 seconds  
for a disk to be inserted.  This is the message with lots of dots that Dave  
Tenny mentioned in his post.  Just ignore this message.

It's not pretty, but it does work.

--
Juan Pineda
juan@apple.com
-- 
Juan Pineda