Re: HP Logic Comparators

Hmm... haven't read the manual real close yet. That would likely mean that
it wouldn't work for the shift registers that I have as they're used to read
playfield RAM. Shoot.

JB

--James Bright
www.QuarterArcade.com
Restored Arcade Games for your Home

----- Original Message -----
From: "Paul Swan" <pswan@lsil.com>
To: "Chris Toseland" <chris.toseland@raxcosoftware.com>
Cc: <techtoolslist@www.flippers.com>
Sent: Monday, July 28, 2003 2:10 PM
Subject: Re: HP Logic Comparators

>
> Hi,
>
> I have bought one of these as well, and it seemed a cool idea but having
> read the manual it has a restricted operating frequency that's below
> video clock in many games.
>
> Has anyone tried using a sig-gen to replace a xtal with a slow clock and
> had better success with comparators as a consequence?
>
> Regards,
>
> Paul.
>
>
> > Chris Toseland wrote:
> >
> > Hi All,
> >
> > This Weekend I've been trying to use my HP Logic Comparator to help
> > fault find some boards and am getting some very hit and miss results.
> >
> > What I'd like to know is are there certain chips that this equipment
> > won't test correctly?
> > I know that if an output is onto a bus it'll read bad but what about
> > simple stuff like 74ls04 it fails that then works fine with a 74ls08.
> > It definately doesn't like 74ls283's.
> > I have tried 3 or 4 different comparison IC's so it's not down to a
> > bad one of them.
> >
> > It even fails chips on known working boards that I'm using for signal
> > comparison with the scope.
> >
> > I'd like to use it so I can some of my backlog out of the way but it
> > seems just to unreliable for serious fault finding.
> >
> > Do I just put it down to tarnished IC legs or something? Any of you
> > have any input?
> >
> > thanks
> >
> > Chris
> >
> > http://www.muppzlab.co.uk
Received on Mon Jul 28 14:05:04 2003