markz@microsoft.UUCP (Mark Zbikowski) (06/14/85)
I understand the disk access, the prompt requires the current directory. Your assessment of the reason for hitting the disk is correct. If you were to change directory into some subdir and then switch disks, you'd see your current directory getting reset to the root. But why doesn't the abort work when the drive is not ready? It seems that the drive error routine that produces this message only takes one character from the keyboard, so how is the prompt screwing this up? This is inside a DOS routine, the prompt shouldn't have anything to do with it! The simple reason is that COMMAND is just a very simple (in some respects) application. It has a one signal handler (INT 24) that displays the prompt and lets the system know what to do. It has another handler that detects when COMMAND itself is going to be aborted. At this point, it cleans up and then reprompts. You can now see why the ABORT response merely causes COMMAND to reprompt. This will hit the disk and generate a new INT 24... Infinite loop. The correct action is to stick a disk into the drive.