Path: utzoo!attcan!uunet!samsung!noose.ecn.purdue.edu!mentor.cc.purdue.edu!andrewtn
From: andrewtn@mentor.cc.purdue.edu (Trevor Andrews)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: 14 mhz Hack
Message-ID: <14787@mentor.cc.purdue.edu>
Date: 4 Oct 90 18:09:12 GMT
References: <3357@mindlink.UUCP>
Reply-To: andrewtn@mentor.cc.purdue.edu (Trevor Andrews)
Organization: Purdue University
Lines: 30

In article <3357@mindlink.UUCP> a665@mindlink.UUCP (Anthon Pang) writes:
>epa@phobos.cis.ksu.edu writes:
>1) 14mhz clock rate doubles the CIA-B timer which causes the floppy drive to
>step at higher rates...such that it doesn't work with normal DOS floppies.
>   A few solutions were proposed--reprogram timer interrupts, half the clock
>output from the 68000 (E line), or software patch from the author.
>
>Use a D-Flip flop 74ALS74 (equivalent to 74F74).  Also connect pin 14 to the 5V
>line.

I am about to implement the 14Mhz Hack and would like to know how
I should half the 'E' line on the 68000.  The schematics look very
clean and easy but I would really rather not have my floppies 
overloaded.  Any help or information on the 'E' line would
be greatly appreciated! I'm not interested in the software patch
or reprograming the timer interrupts. Unless that is a lot easier
than the halving of the 'E' line.  Will I lose any performace gains
by keeping the 'E' line at 7Mhz?  I wouldn't think so...

P.S. how fast does my drive have to be so it won't experience the
     slow spin up problem?  I have heard of someone doing the
     Hack and replacing his internal drive with a 5ms one! But
     who wants to buy a drive when the hack is less than $20?

Thanks for you time,
Trevor Andrews

-- 

The Trev