I think you can switch disks pretty much any time. The Alto doesn't swap to disk so the disk is only being used when you're loading a program or loading/saving

I think you can switch disks pretty much any time. The Alto doesn't swap to disk so the disk is only being used when you're loading a program or loading/saving a file. As far as how it's used, think of the Alto's disk more like a floppy drive than a hard drive. (Although since it takes a minute for the disk to spin up to speed, you don't want to switch disks too often.)