>>me and my friends ...

My friends and I...

If you're going to be a pointless language pedant, it really helps if you don't fuck it up.

OP said:

> me and my friends together built an 8 bit CPU…

– and if one replaces that with your suggestion:

> My friends and I together built an 8 bit CPU…

– you'll find that you are, gleefully, wrong.

For those unaware, the simplest test for 'me and x' vs. 'x and I' is that, in the latter case, you should be able to remove 'x and', and have the sentence still make sense.

For example, 'Me and Lucy went to the shops' is technically incorrect, because 'Lucy and I went to the shops' makes sense if we remove Lucy. 'I went to the shops'.

The pendant's adjustment fails this test:

> I together built an 8 bit CPU

I downvoted the original comment because grammar pedantry adds nothing here. But if you're going to correct a pedant, you've got to be right. You're applying a test you don't understand and you messed it up.

"I" is the subject of the sentence, or the person who is doing the thing. "Me" is the object of the sentence, or the thing that is receiving the action. Since he and his friends are the ones who did the building, "I" is the correct pronoun.

Going back to the test you gave, the correct way to apply it is to replace entire the noun phrase with "I" or "me". The noun phrase here was "me and my friends together". "I built an 8 bit CPU" vs "Me built an 8 bit CPU". The former is the obviously correct one.

Obviously one needs a lesson in English sentence construction. I had those lessons beginning in grade school and ended in college. I'm not sure you've had anything beyond the internet.

Me together built... doesn't make sense either