Re: How much of a ][ is needed to twitch?

[russotto@grace.speakeasy.net (Matthew T. Russotto)]

In article <45ce84be$0$83739$c30e37c6@lon-reader.news.telstra.net>,
Tristan Mumford  <xtristan.xmumford@xgmail.xcom> wrote:

>I'm in the mood to attack my infirm clone to try to get it running again.
>As it is I'm fairly certain the problem isn't the CPU or ROMS. About a month
>ago I was doing a random pull test. Essentially pull a chip, power up and
>see what changed. The most difference that pulling a chip made was making
>the screen all white. Other than that all that really changed was the
>pattern of 'garbage' on the screen. Although I'm sure the garbage pattern
>would probably tell a story to some people it doesn't to me.

This is probably NOT a good way to diagnose the machine.  The garbage
pattern really says nothing except that the character generator and at
least some of the RAM is working.

>I'm hopeful of a solution that doesn't involve me blindly replacing chips
>until I find the culprit.

That has a better chance of succeeding.  Using a scope or even just a
multimeter and the schematic will help.  First thing I'd check is
probably to see if the processor is running at all (see if the clock
phase outputs are changing).
-- 
  There's no such thing as a free lunch, but certain accounting practices can
  result in a fully-depreciated one.