From: boyd@shmop.cs.fsu.edu (Mickey Boyd)
Subject: rolling your own ST hard drive
Reply-To: boyd@nu.cs.fsu.edu
Organization: Florida State University Computer Science Department
Date: Wed, 7 Oct 92 05:02:25 GMT

I have been seeing a lot of hard drive questions lately, so I thought this 
would help.  I post it about one a year, when these questions come up.

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In article <bg258s1421.03a3@sycom.mi.org>, bg258s1421@sycom.mi.org (Burley Good) writes:
>I am looking for an inexpensive HD a starters HD. I am looking for a used
>maybe 20m or more CHEAP!!!

You might want to try rolling your own.  It is very easy for the ST.  You 
need:

	A host adaptor
	A power supply
	An enclosure 
	A SCSI drive

I recommend the ICD Host adaptor.  It has (IMHO) the best software, which is 
updated frequently (and available free).  They also provide a very easy way 
to add a battery backed up clock to your ST (if you don't have one already,
they can be bought with or without the clock).  I also like ICD's because they
report any "sense codes" the drive communicates to the user.  I have only 
seen one ("read error with recover", induced by dropping something heavy on 
the desk while the hard disk was reading), but I find it reassuring that 
any weirdness at the device level is reported directly to me (it pops up in 
the corner of the screen, by the way).  Price is about $80 at last look.  
Without the clock, you save $10.  Order the SCSI connector cable whereever 
you get the host adaptor, and make sure to ask for a dual drive one with a 
red wire denoting pin one (to make the installation easier).          

Power supplys are cheap.  Just pick up an old XT power supply for ~$30 from 
computer shopper.  If you can find a junked PC, you can get one for free.

Enclosures can also be cheap.  You can buy one of those huge old style XT 
cases for about $30 from computer shopper.  This will hold all the hard 
drives you will ever want!  Buy a tower stand for $5 and stick it on the 
floor (the ICD cable is nice and long for this).  You can also go all out 
and buy an enclosure which will fit under your monitor (mine houses 2 5.25"
devices, has a front mounted lit power switch, mates perfectly with the 
ICD board, etc) with power supply for about $125.  There are several places 
that sell these for the ST, two being Toad Computers and D&P Computer 
Supply.  Email if you want their 1-800 numbers.  Again, a junked PC is the 
absolute cheapest way to do this.  If you can get ahold of granny's old 
IBM XT, you are in fat city.  A nice side bonus is that the old PC motherboards
make great wall hangings (big fat traces, lots of chuncky looking components).
Old PC's are really easy to find, now that everyone is going to 80x86 
machines.

Now, the SCSI drive.  These can be bought from Computer Shopper.  All you 
need is a bare SCSI device, no other boards or anything.  The ICD host will 
work with just about anything, but there is a very large list of already
tested drives that comes with the host adaptor (which I could probably 
email to you also).  New drives are very cheap nowadays, but if you want to 
really save money you can get a refurb.  Several of the refurb places will
guarantee their drives for X number of years (X varies with the particular 
company), so they can be a viable way to go. 

Anyway, you will now have your hard disk.  You bolt down the drive and 
host adaptor (you can drill some extra holes in the case, or use wire-ties
or whatever), connect the two, plug in the power cords (the ICD comes with 
a little splitter which connects to a standard PC type power cord), hook up 
the DMA, and boot up.  It is very simple, and is not easily botched up.  
You only need to pay attention to:

	SCSI id jumpers set to some reasonable value
	SCSI terminator pack plugged into the drive (should come this way)
	SCSI connector from drive to DMA is right side up on both ends
	Nothing wiggling around

The first two can be checked via the manual that will accompany the drive 
(make sure you ask for it, some places assume you already have one), usually 
a 1 page Xerox.  The third can be verified by checking that the red wire 
side of the ribbon cable is near pin one (which is marked on the board either 
by a number or by a square solder hole instead of a round one).  If the 
cable is in backwards, the red end will be at the other end of the connection
(quite often it is pin 2 that is marked, but you only need to know which end 
of the connector the numbers start on, and match it with the red wire).  These
are the only two possibilities.  You cannot mess up the power connections or 
the DMA connection (they won't go in wrong). 

The reason you wanted a dual drive cable is so you can easily add another 
device in the future.  You merely have to plug it into the other receptacle
on the cable, remove the terminating resistor pack off the middle drive on 
the cable (the one on the plug closest to the computer), and check to see 
that the SCSI id jumpers are set to two different numbers.  Oh, by the way, 
the ICD supports the Syquest SQ555 (the 44mb removeable cartridge drive) 
without any special concerns.  Since the Syquest is a SCSI device, you can 
hook one of these up just a easily as you could a regular fixed disk drive.
These only cost about $320 bucks nowadays, with 44mb cartridges going for 
~$60.  

It really is easy, and there are plenty of computer tinkerers around to 
look over your shoulder and verify what you do.  You can also use a setup 
consisting of a host adaptor, SCSI controller board, and ordinary PC type
hard disks, but you add complexity to the system and lose performance this 
way.  Straight SCSI is much cleaner, and usually much faster (SCSI devices 
have their controller boards "built in", communicating with the SCSI standard).

If you do get a hard disk, you should immediately buy Neodesk 3 and the 
Universal Item Selector III.  They will make life much nicer.  Also, beware 
of buying too small a hard disk.  Megabytes are like potato chips.  I have a 
buddy with a 105mb quantum drive, a 320mb Hitachi, and a Syquest SQ555 with 
6 cartridges all hooked to his ST, and he still complains about not having 
enough disk space!  I have not yet gone that apeshit, but I think Mr. Visa 
might have to talk to Syquest Corp. pretty soon.  Oh, notice the my friend 
above has three SCSI devices hooked to his ICD.  This just requires a 3 plug 
cable.  The ICD can support 8 SCSI devices, and you can hook up multiple 
host adaptors if you really need to (like if you get given a box of 10mb 
SCSI drives :-).

Please feel free to email questions.  The above is IMHO, direct flames 
elsewhere. 
  
-- 
  ****************************************************************************
  *                              Mickey Boyd                                 *
  *                         Systems Administrator                            *
  *          Florida State University Computer Science Department            *
  * email:  boyd@cs.fsu.edu  Office:  (904) 644-7339  Pager:  (904) 657-6425 *
  ****************************************************************************
Newsgroups: comp.sys.atari.st.tech