Re: Such memories...
I first encountered the Commodore PET in the mid 1980s when I worked for a large Government organisation and the head tech manager bought a couple for us "to play with". We didn't get very far until we bought a copy of Raeto West's invaluable handbook. I still have my copy in the attic but I might just put it on the market to see what price it will fetch! https://www.amazon.co.uk/Programming-PET-Raeto-Collin-West/dp/0950765007