Talk:OSBYTE &00

Calling &FFF4 on BBC BASIC on DOS or Windows always returns the character under the cursor - all calls are implemented as OSBYET 135. In most cases this results in calling OSBYTE 0 returning 32, a space character, as a program will normally call OSBYTE 0 when there is nothing under the cursor.

As the character under the cursor will always be a printable character a better test is to test for >=32, so use code such as:

IF os%>=32 THEN dir$="\":ext$="."

etc.