Crashes when selected disk drive is not ready

[Tek-User]

Here is the one issue I know of so far. The 2402 or 2402A program appears to crash if the used selects a disk drive that is not "ready". The most common reason for this is that there is no floppy in the selected drive.

It isn;t actually crashing, DOS is looking for used input from the KEYBOARD and is trying to display an error message on the monitor. But the 2402/2402A is typically running without a keyboard or monitor. The program running on the unit is interacting with the oscilloscope for the expected input and is be unable to handle DOS interraction via the oscilloscope.