Understanding shift registers
Howdy Gang,
I have felt inspired by watching Ben Heck's pinball building from scratch with a propeller chip and thought it would be good for me to understand the various ways he is using the input/output of shift registers to increase his I/O for the propeller. I know he uses the 74x595 for output and the 4021 series for the input but I have never seen a 4021 with cascade logic like you can do with the 595's. Looking at the specs from www.classiccmp.org/rtellason/chipdata/bu4021b.pdf I have not been able to figure out how to 'cascade' read several chips. Any help would be appreciated.
I have felt inspired by watching Ben Heck's pinball building from scratch with a propeller chip and thought it would be good for me to understand the various ways he is using the input/output of shift registers to increase his I/O for the propeller. I know he uses the 74x595 for output and the 4021 series for the input but I have never seen a 4021 with cascade logic like you can do with the 595's. Looking at the specs from www.classiccmp.org/rtellason/chipdata/bu4021b.pdf I have not been able to figure out how to 'cascade' read several chips. Any help would be appreciated.
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Comments
I found this site that kinda details what I was thinking it was doing:
arcadecontrols.com/arcade_sneskey.html
I kinda felt the Q8 was what you connect to the next in line. I assume the Q6 Q7 Q8 were done to allow different counting styles?
You're welcome.