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From: hale@hpfcdj.HP.COM (Bill Hale)
Newsgroups: comp.sys.mac
Subject: Re:Strange Plus/HD problem;SOLVED!
Message-ID: <17240002@hpfcdj.HP.COM>
Date: 12 Jul 90 22:43:16 GMT
Organization: Hewlett Packard -- Fort Collins, CO
Lines: 67


	Thank all of you who responded (original message follows).
	Lots of good suggestions, some of which I had tried.  Frustrating
	problem solved!

	The gentleman from Dupont/Santa Clara hit the problem directly
	on the head.

	The Mac+ does not have the same bootroms that the MacSE has.
	An important distinction is that part of the bootcode that
	is in the SE ROMS is actually resident in a partition on the
	hard disc for the Plus system.

	As I had used the factory SE supplied 20mb disc, this partition
	was missing, which prevented the Plus from booting.

	Per the suggestion, I re-initialized the disc using my Ehman
	HDD 1.5 utility, and the disc now performs flawlessly with the
	Plus.  Apparently, the Ehman software provides the required
    	partition.

   >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

	Here's a Plus/HD problem that has stumped all the local MacExperts...

	I removed a factory supplied 20mb Miniscribe 8425-S HD from an SE
	to update with an SC-40. The SE continued to work flawlessly.

	I then changed the SCSI address on the 20mb to 2 using Miniscribe
	provided data, and installed it in a CMS housing having DB-25
	connectors.  The 20mb had terminations (since it had been installed
	in the SE) and termination power is diode or'd from its own internal
	supply so it is present even if the computer does not supply it.
	I used a DB25 two-ended cable 18" long to connect it to the Plus.

	The result is that the Plus recognizes the HD on the correct
	select code; I can move files all over the place with no errors; 
        but I *can't* get the Plus to boot from this disc. (I get the "?"
        icon).

        If I connect the same 20mb externally to the *SE*, it boots from
	it just fine, and I can transfer OS control back and forth to its
	internal HD by simultaneously pressing "Command" and "Option" and
	double-clicking the Finder.

	The Plus I am using to test this system is normally connected to
	an Ehman-40 and it boots from it just fine.  To try to narrow down
	the possiblilties, with *both* the Ehman and 20mb connected to the
 	Plus, I copied the *exact* System folder from the Ehman--that boots
	the Plus successfully--onto the 20mb (after removing the original
	System, of course). 6.0.3 I think.

	The Plus still won't boot from the 20mb (the SE still *will*); if
	I try to change OS control to the 20mb after booting off the 
	floppies, (as described above) I get a message like ~ "System
	incompatible version."  How can that be? 

	Many similar problems have been discussed on the net.  I looked
	thru the responses and was unable to find anything relevant to 
	this problem.

	Any MacNetWizzard able to spot the problem? I am so desparate I
	might have to buy another disc to try to avoid this problem!
	
	Bill Hale  hale@hpfclm.HP.COM  303-229-3037  HP Ft Collins CO
	Thru ether K0QA; In ether N33HP; snail 3404 E. Harmony
	Ft Collins, CO 80525 home 303-663-1346 call collect with solutions!