what happens when you upload a sketch to a uno?

does the uno dump any previous sketches when you upload a new sketch to a uno?

yep, just starting out and trying to understand if the uno 'fills up' with sketches and needs a reset/sketch dump, after the uno is 'full', somehow...

thank you for any replies that help me understand the little guy, with the big heart!

Every time you upload a sketch to the Uno, the old sketch is overwritten. So you can only have one sketch at a time on the Uno and you don't need to worry about it filling up with sketches.

Thank you!

You're welcome. I'm glad if I was able to be of assistance. Enjoy!