Why can I use my original 1541 disks in my PC 5 1/4″ diskdrive (B:)?
It is technically impossible to read a 1541 disk in a PC diskdrive. The reason is that PC and 1541 uses completely different systems for magnetic recording, MFM versus GCR. Note also that the original 1541 is much more than just a disk drive, in fact it is a complete computer, with its own CPU and RAM/ROM. The PC’s diskdrive is just mechanics with simple read/write electronics, with no intelligence of its own.