Re: Testing XY games on oscilloscope

When I used a scope for this purpose, I used a TTL inverter, anything you
like in the 7400 series. They don't require any additional circuitry to
run, only power and ground. They are dirt cheap, and you can buy them at
any electronics store.

Joel-

-----Original Message-----
From: Matt Rossiter - Verio Southern California <matt@rossiters.com>
To: vectorlist@lists.cc.utexas.edu <vectorlist@lists.cc.utexas.edu>
Date: Thursday, November 18, 1999 5:46 AM
Subject: Testing XY games on oscilloscope

>I do almost all of my board testing on the bench now with either a small
>5" tv for raster games or an oscilloscope for XY games. I try to use up
>as little space as possible.
>
>I have one question about using the oscilliscope with XY games. My
>oscilloscope has a Z input as well as an XY. When I hook up the Z probe
>to the game the display goes completely blank. My roomate suggested that
>I probably need to invert the signal in order to get the display I'm
>looking for, which is the game without the retrace lines. He says that it
>should be relatively simple to invert the signal with a transistor and
>maybe a couple of resistors.
>
>So - again - before I reinvent the wheel - does anyone already use a
>device that does this? Maybe some kind of inverter with a coax connector
>- or does anyone have something they've already tried in terms of removing
>the retrace lines on an oscilloscope?
>
>The main reason I want this is so that I can read errors during the built
>in self tests.
>
>
>Thanks....
>
>
>Matt
>
>
>
> V E R I O
> Orange County . Los Angeles . San Diego
>_____________________________________________________________________
>
>Matthew J. Rossiter email: mrossiter@verio.net
>Customer Services Engineer http://socal.verio.net
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Received on Thu Nov 18 10:03:19 1999