Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!nfsun!eklektik!danbabcock
From: danbabcock@eklektik.UUCP (/dev/ph1)
Newsgroups: comp.sys.amiga.tech
Subject: Drive step rate slowdown: my solution
Message-ID: <2859@eklektik.UUCP>
Date: 5 May 90 01:37:21 GMT
Reply-To: danbabcock@eklektik.UUCP (/dev/ph1)
Organization: Computers, Gerbils, and Games in the Basement, Pgh, PA
Lines: 30

gfre@pawl.rpi.edu (gregory m stiegler) wrote:

>Ok, now for the big question. Does anyone have a way to slow the drives
>down? The circuit seems to work fine but you can't boot.  I assume the E
>clock is being sped up along with the processor. Any fixes for that?
>--==Niemand==--
>gfre@pawl.rpi.edu

- all the following assumes kickstart 1.3 -

There is a simple way to slow the drives down. Just replace the longword
at address $fea176 (which used to be $6d000024) with $6d24e388. What could
be easier?

If you can boot (perhaps with an autobooting hard drive) but still want
to slow the drives down - and can't modify kickstart - there is also a
software solution. In fact, I wrote a program to do it. The program
actually has the complete trackdisk.device code imbedded in it - with
all absolute addresses converted to assembler labels! Then I simply pull
a NoClick-like stunt to redirect the trackdisk tasks to the RAM-resident
code. This also allows me to fix the infamous RawRead/RawWrite bug.
If you want a copy of the program, please send me a disk (email from this
site seems to be lost in a black hole...) to the address below, or contact
me on People/Link.

-- Dan Babcock
1106 Jefferson Road
Pittsburgh, PA 15235
Phone: (412)-373-1753
People/Link: DANBABCOCK