On Sun, 13 May 2001 20:01:35 -0500, you wrote:
>Quite interesting. So the MK4801 was the cheaper alternative to a 16K ram - even
>though it was technically the same chip. Hmm.
Not at all uncommon - and actually, the MK4801 was an alternative to an
8K RAM, not a 16K RAM, since half of the matrix was defective. :)
>Well, I took a look through some Gottlieb schematics, and it seems that both 4801
>SRAMs have pin 19 labeled as "L" with a bar over it. Am I assuming correctly that
>this means logic Low?
Afraid not... it means a signal called "L-not"; i.e. a signal called
"L", which is active when low instead of high. What "L" means is anyone's
guess, unless you have the data sheet...
>Following the traces on the board, it appears each pin is connected to another
>device (the schematics only show a connection to a resistor). I know I'm showing
>my ignorance, but would I lift pin 19 on these 6116 RAMs and still have a
>functioning external circuit?
Lift pin 19 on the 6116 chips _and_ tie it either to ground or to +5
through a 10K pullup resistor. (Tie each one separately; don't connect
them all to one pullup.) Don't leave it floating, or signal noise will
make the 6116 keep flipping back and forth between the two 8K banks
randomly.
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"There is no virtue in suffering fools gladly, for it only encourages them to
persist in their foolishness." --Kehlog Albran
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solarfox@DON'TMESSWITHtexas.net (Gary Akins jr.)
http://lonestar.texas.net/~solarfox
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Received on Sun May 13 19:09:57 2001
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