🚀 go-pugleaf

			Home made SCSI Hard disks.
	When I started this project I new nothing about how to go about it, I 
have since learn't a great deal but obviously not enough to solve all my 
problems. I am therefore appealing to the net for a possible solution to my 
dilemma.
AIM:	To build a home made SCSI hard disk system using 2x20Mb winchesters
	(that happened to be lying around) for as cheaply as possible (sound
	familiar  :-)  ).
HARDWARE  Macintosh Plus (version 1 ROMS)
USED:	  Adaptec hard disk controller card model ACB4000-A
	  2x20Mb Epson winchesters, 5 1/4", ST412/506 interface,4 heads, 614
	  cylinders (ie. fairly generic).
SOFTWARE  System 3.2, Finder 5.3
AVAILABLE:Format, a low level format program by Tim Standing (MacTutor June 87)
	  SF&I, a SCSI disk formatter and installer by Ephraim M. Vishniac,
	  version 0.92.
	  EasyTools, a formatter and installer by D-K research Inc. ver. 2.19
	  Apples HD SC setup 1.4, 1.5 and 2.0.
PROBLEM:  After doing a low level format using 'FORMAT' I was then able to 
	  format and instal the drives using 'SF&I' or 'EASYTOOLS'. Apples 'HD 
	  SC 1.4, 1.5 or 2.0" didn't work (no great surprise). The system works
	  sort of, in fact I used it to write this. However, the Mac only knows
	  that one hard disk exists. The Adaptec card has facilities to control
	  two hard disks but I can only ever access Disk 1. Disk 2 CAN be used
	  PROVIDED that I configure it as Disk 1 (and likewise Disk 1 as 2).
MY          (1) Although I constructed all the cabling myself I am confident 
CONCLUSIONS:	that no hardware problem exists. As I noted above both drives
		have worked, but separately, ie. for the second drive to be used
		the jumpers on the winchesters must be changed and the 
		connnectors for the Drive 1 and 2 data lines must be swapped at
		the controller card end. The control lines do not need to be
		swapped. I get the impression that the 2nd drive is not 
		recognised by the formatting program as having a unique address
		and therefore can't be accessed.
	    (2) I am therefore led to believe that I have a software problem. I
		think I've heard that phrase somewhere before :-). After much
		re-reading of literature (yes I'm running out of ideas) I note
		that those people who have made their own SCSI drives tend to
		use only one winchester, the author of 'FORMAT' included. Has
		anyone controlled two winchesters off the one card? if so please
		respond. After examining the code for 'FORMAT' I note that that
		the only address that it seems to know about is the SCSI bus
		address (in this case '0'). Now I don't know if the drive card
		is smart enough to work out that there are two separate drives
		and should be able to format both or whether need to tell it
		via the low level format program that I am interested in 
		address 0 Drive 1 or address 0 Drive 2? If so how? I suspect
		the latter, my impression is that during low level formatting
		the Mac should provide information describing each drive which
		the controller card stores on the disk and which is read into
		the controllers RAM during power up. From my experience at work
		with IBM PC clones the low level format routine does give you
		the option of formatting one or more drives. 'FORMAT' doesn't
		appear to have this facility. For those people with experience
		with the Adaptec ACB4000-A card; does the manual give any clues
		as to how a low level formatter should adress both drives and
		so enable me to modify 'FORMAT'. When I recieved my card I found
		no documentation, a quick call to the agents gave the reply 
		'That's a separate invoicable item'. I have therefore gone this
		far without a manual. At work we find that IBM PC controller
		card manuals are generally useless for setting up clones. I 
		will get a copy of the Adaptec manual if people advise that it 
		is useful but if it isn't then there's no point.
		Any feedback on whether I'm on the right track or any 
		information on how to get both drives operational would be
		appreciated.

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John Haub				ACSNET: jgh@atom.oz
C.S.I.R.O.				ARPANET: jgh%atom.oz@seismo.css.gov
Division of Mineral and Process         UUCP: {seismo,ukc,prlb2,ubc-vision}!
Engineering				       munnari!atom.oz!jgh
Lucas Heights Research Laboratory	       
Private Mailbag 7 Menai 2234
Sydney
N.S.W.
Australia
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