Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!csd4.csd.uwm.edu!dannys
From: dannys@csd4.csd.uwm.edu (Daniel Shurilla)
Newsgroups: comp.sys.amiga.hardware
Subject: Sony MPF11 to A1000
Summary: Why don't I need RDY to work?
Keywords: $50 for a 3.5" drive is a good deal !
Message-ID: <3342@uwm.edu>
Date: 9 Apr 90 15:52:48 GMT
Sender: news@uwm.edu
Reply-To: dannys@csd4.csd.uwm.edu (Daniel Shurilla)
Organization: University of Wisconsin-Milwaukee
Lines: 28

[eat this]


This weekend I sucessfully interfaced two Sony MPF11 3.5" disk drives
to my A1000. The motor-on latch and autoconfigure circuit was obtained
from a local BBS but was evidentally grabbed from a Commodore schematic.
The Sony MPF11 drive can be purchased from Jameco Electronics for $49.95.
That's $100 + $20(small parts) for a dual drive!

The question :
The Sony drive provides the diskchange signal (CHNG pin11) but doesn't
provide the ready signal (RDY pin1). The RDY line should become active
500ms after motor on. I left the RDY line connected to the autoconfigure
part of the interface circuit but not connected to any drive signals.
Why does this work? Does software wait 500ms after motor-on before doing
any read/writes? I would think you would wait for the RDY line to become
active before doing read/writes but this must not be the case. I wonder
what the recommended method is, wait for the hardware RDY line or wait in
software for 500ms to pass.

Another Question :
What is software doing to make the drives click? (stepping past trk0 when at
trk0 ?) Is there any hardware modification I can add to my interface circuit
to stop the #%$@ing clicking ?

thanks

dannys@csd4.csd.uwm.edu