reading simultaneous keys pressed

[boriel]

Use the multikeys function in the library which returns non zero (True) if ANY of the given keys is pressed.

Code:

#include <keys.bas>

DO
IF MultiKeys(KEYSPACE | KEYENTER) THEN
    PRINT "Space or Enter pressed"
END IF
LOOP : REM Repeat forever since no condition specified

Predefined key constants are in the KEY.BAS file. Read there.

Notice you can use | as in C or bOR to test for multiple values simultaneously.
So the above test checks for ENTER or SPACE pressed.
The function is much faster than INKEY$ and can check multiple keys pressing (limited by the ZX hardware)