Re: Asteroids Deluxe RAM Problems (was: 2114 RAM speed)

-----Original Message-----
From: Chris Loggans <cloggans@yahoo.com>
To: vectorlist@synthcom.com
Date: Sat, 24 Aug 2002 10:29:16 -0700 (PDT)
Subject: VECTOR: Asteroids Deluxe RAM Problems (was: 2114 RAM speed)

>
> Thanks to David Fish for sending me the data sheet on
> the SCM21C14-4 RAM. Unfortunately, that didn't
> provide the smoking gun I was hoping for. Maybe
> someone here could provide a little more insight into
> the problem I was having.
>
> Problem: Asteroids Deluxe board. Reporting a bad
> program RAM in self test. When tested with a Fluke
> 9100, it tested fine. Swapped out said RAM and the
> board now works. The only conclusion that I could
> draw from this was that the RAM was too slow for this
> application. Unfortunately, from the data sheet that
> David sent, it shows that the RAM was a -200 ns part,
> which should be more than sufficient for this
> application.
>
> Any thoughts on why this particular RAM wouldn't work
> on an Asteroids Deluxe board? The only thing that
> caught my attention on the data sheet was a statement
> that says: "For NMOS 2114 replacement applications,
> note the timing differences for /CE; where /CE access
> is required to be faster than address access, use the
> SCM2114AL." However, I don't think this would apply
> to the Ast Dlx board since the address lines are
> already stable before the /CE is triggered (by the
> address lines). I'm stummped.
>
>
2114's are crap, they are always causing trouble.

I try to replace them with a 6116 whenever i can.
(NO - THEY DONT FIT IN THE SAME SOCKET!)

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Received on Sun Aug 25 02:26:23 2002