Very interesting! Wild to think that such a large chip would be used to drive a calculator. Thank you for the information.

Cranked up the zoom to check and yep, it does appear to be a part number, or batch number. Both delidded chips have the same number (75298). Also present is an MOS logo. Not sure what the "2 34" below and to the right of the P/N is. Maybe batch/panel?

Thanks guys for your input! I've gone and found a microscope to take better pictures of the die. It should be noted that, because I don't have the right size objective to fit the whole die in one shot, this is a very crude (it's not even square) composition of ~9 or so photographs, taken with my ...

Hello, I've been going through some things left to me by a family member, and found these. As I understand it, 6501s are pretty rare, what with Motorola suing MOS back in the day. I have no real use for these, so I was hoping to ask the experts here what they though I should do with them? If you're ...