[comp.sys.mac] 2nd hard drive in Mac II

jlh@stech.UUCP (Jan Harrington) (05/18/89)

I am considering getting a second internal hard drive for my Mac II. Since
there is only one floppy drive, I understand that the second drive should fit
without a problem.

Is there anyone out there who can give me some information about installing the
drive once I get it? Where does it go? (Next to the floppy, where a second
floppy would go?) Where does it plug in? (Sorry, but I'm rather ignorant
about these sorts of things...)

Thanks a million.

Jan Harrington
Scholastech Telecommunications
husc6!stech!jlh or allegra!stech!jlh

*************************************************************************
	Miscellaneous profundidity:
		"No matter where you go, there you are..."
			Buckaroo Banzai
*************************************************************************

glen@cory.Berkeley.EDU (Glen Rosendale) (05/19/89)

I know this has been seen before but the mail bounced on me so...

In article <1108@stech.UUCP> Jan Harrington writes: 
>I am considering getting a second internal hard drive for my Mac II. Since 
>there is only one floppy drive, I understand that the second drive should fit
>without a problem.  
> 
>Is there anyone out there who can give me some information about installing 
>the drive once I get it? Where does it go? (Next to the floppy, where a 
>second floppy would go?) Where does it plug in? (Sorry, but I'm rather
>ignorant about these sorts of things...)  
> 
>Thanks a million.  
>
>Jan Harrington 
>Scholastech Telecommunications 
>husc6!stech!jlh or
allegra!stech!jlh 
>
>*************************************************************************
>	Miscellaneous profundidity:  >		"No matter where you go,
there you are..."  >			Buckaroo Banzai
>*************************************************************************


Interesting you should ask this question...I did just this about 3 months
ago.  Here's the considerations...

1.  Physical space: the spot next to the floppy drive will hold a 3-1/2"
    half-height drive.  I got a Quantum 80MB drive from a local Mac store
    and I recommend it highly.

2.  Mounting:  I had to mangle the mounting bracket that came with the
    Quantum drive to get it to fit (sort of).  I don't know of any pre-
    configured HD brackets that will fit there so this part of the process
    seems unavoidable.  Also, if your other drive is a 5-1/4" device it may
    get somewhat crowded in there, but things can be made to fit.

3.  Connections:  this gets a *little* tricky.
    a. The power connection is easy; SCSI devices (the ones I've seen,
       anyway) have a standard power connection and for once Apple used a
       standard part on the motherboard.  You can get a "Y" connector at
       almost any general computer/electronics store; I got mine at a local
       wirehead shop for about $5.00.
    b. The SCSI connection is not difficult but can be tricky.  You want to
       create (somehow) a cable with 3 50-pin connectors on it, at either
       end and near the middle.  The simplest way is probably to get just
       the connector you need; it's a press-fit 50 contact connector, mine
       cost about $2.00.  Since I wanted to keep my original hard
       drive connector intact I bought three connectors and about 18" of
       50-conductor ribbon cable and made a new connector.  When you make
       a cable (either way) make sure all the connectors are oriented the
       same way on the ribbon cable (they have a notch in one side for this).
       Anyway, then all you do is attach one end to the motherboard, the other
       end to a drive, and the middle one to a drive.  Which brings up..
    c. Terminating resistors and SCSI ID's...The drive at the *physical* end
       of the chain should have its terminating resistors in place, and the
       one in the middle should have them removed.  If you're not sure about
       where they are, they'll be 3 or 4 single in-line packages mounted in
       sockets on the drive controller card adjacent to the SCSI connector.
       Remove (and save, needless to say) all the resistors on the drive that
       will be in the middle of the chain (as far as I know, all internal SCSI
       drives are shipped with terminating resistors installed).
       SCSI ID numbers...One of the drives should have an ID number of zero:
       this tells the Mac to wait for its boot process till this drive is up
       to speed.  This should probably be the drive you'll be booting from
       (in my case, the Quantum).  The other drive's ID doesn't matter as
       long as it doesn't conflict with any other SCSI devices.


 Hmm...I think that's about it; the whole process took me a couple of hours of
 trial and error (and some broken 50-pin connectors; be *careful* with them).
 If you want more information you can email me (although my first attempt to
 mail to you bounced so I'm not sure how I'd get in touch with you....)

 Hope this helps enough to let you do this; it's worth it when you see all
 that space online...

 glen rosendale (glen@cory)
 

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