Help with 4021 shift register

Oldbitcollector (Jeff)

Question:

Does the 4021 shift register require 10k pull-ups on each of it's inputs?
I'm getting some weird results from one I scabbed from a controller and
can't determine if I killed it (CMOS chip) by handling it, etc or if I simply
need to add some pull-ups to the lines.

Nintendo appears to have pulled together their original nintendo controller
without the need of pull-ups, what about my clone controller?

Thanks
OBC

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CannibalRobotics

Those old 40 series CMOS chips are notoriously sensitive to static. What are you interfacing to/from and how's it powered. Each technology, NMOS, TTL, CMOS has a different connection protocol.

I was working on this with someone on another thread and·I ran accross a recommended practices sheet by National Semiconductor·I think. It had all of the connection recommendations and practices for all of the technologies. Probably still have it on my office computer. I'll try to rember to post it tomorrow for everyone, it's a good resource.

Jim-

PS: Yes, the inputs will drift up and down if not nailed in one direction or the other.




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PJAllen

I'd have my control inputs (L, R, E) in a known state.