These days I would say just buy an rPi 4B+ ... it's tiny, it's light, it doesn't need noisy fans (the first bane of old laptops), it doesn't require ancient non

These days I would say just buy an rPi 4B+ ... it's tiny, it's light, it doesn't need noisy fans (the first bane of old laptops), it doesn't require ancient non-uniform battery technology (the second bane of old laptops), keyboard and screen can be upgraded when destroyed (the third and fourth banes of old laptops), it's cheap, it's fast enough for nearly anything. Invest some extra in a wireless keyboard and mouse, optionally a portable screen or second hand Android tablet https://passivetech.com/2020/07/30/how-to-use-an-android-tablet-as-a-raspberry-pi-display/ https://passivetech.com/2020/07/30/how-to-use-an-android-tab... for the tiny subset of situations in which you really need to compute and don't have one available at home/office/hotel, and buy a USB battery pack.