>This was basically impossible to do in the early personal computer era, before memory protection was a thing. So MacOS, Windows pre-NT, AmigaOS etc were all bu

>This was basically impossible to do in the early personal computer era, before memory protection was a thing. So MacOS, Windows pre-NT, AmigaOS etc were all built around the assumption of applications reading each other's memory. Very true. The user had a different option for that, since DOS was basically a program loader, and only one thing ran at a time, they could boot into program A, and use it with disks Q,R,S and know that no other disks could be corrupted. Then later, boot into program B, for disks X,Y,Z. It was capability based security, where each diskette was a capability. (Before hard drives ruined that trust model)