Path: utzoo!utgpu!attcan!uunet!super!udel!gatech!rutgers!ucsd!ucbvax!agate!sag4.ssl.berkeley.edu!johnf
From: johnf@sag4.ssl.berkeley.edu
Newsgroups: comp.sys.amiga.tech
Subject: 5.25" drive question
Message-ID: <13132@agate.BERKELEY.EDU>
Date: 10 Aug 88 10:25:38 GMT
Sender: usenet@agate.BERKELEY.EDU
Reply-To: johnf@sag4.ssl.berkeley.edu ()
Organization: University of California, Berkeley
Lines: 36


Hey folks, 

     I have a small puzzler, the answer to which I suspect might
be common knowledge among the Amiga cognoscenti (I am a neophyte of 3-4 months).
I decided it would be fun to try and hook up a surplus 5.25" drive to my 
external drive connector (I have an A500).  I built a small interface circuit 
from an article on one of the Amicus disks written by someone named Marty,
which basically translates the Amiga MTRXD* signal into a form expected
by IBM-compatible drives, got a power supply for the drive, and made
up the cables.  Finally, I changed the example mountlist entry for the 
5.25"drive to reflect the fact that I was hooking it up as DF1:

     After playing around with the jumpers for a while on the drive (a
1/2 height, 360K Mitsubishi model M4851-352U) I have it in a
configuration where it _almost_ works.  The hardware seems to be in
fine shape, but mounting the drive is peculiarly difficult:

  1) If there is a disk in the drive when I reset the Amiga, the drive
     is automatically mounted as df1:, but the mountlist entry is ignored.
     The Amiga assumes that it is an 80-track drive.  Thus, when I try
     to format a disk, all goes well until the drive bangs its head
     against the wall trying to access tracks 40-79.  Kind of amusing, actually.

  2) If there is no disk in the drive at boot time, the drive is never 
     recognized.  Mount does create a logical device DF1:, but format reports
     an inability to locate its handler.  I note that its 
     handler, "trackdisk.device", is nowhere to be found on disk, but I
     assume that it is in the roms or something. I tried PCFormat from 
     the Extras disk, though I ultimately want to use the drive as
     an AmigaDos disk, but it just gurus.

I just can't seem to get the computer to mount the drive properly.  Any takers?

john flanagan
johnf@sag4.ssl.berkeley.edu