When using variables named IN or PR, compile fails due to assuming you are referencing IN # or PR #
java.io.IOException: Expecting: [IN, #]
java.io.IOException: Expecting: [PR, #]
For example:
10 PRINT "SETTING UP VARIABLES...."
20 OUT = 10
30 IN = 40
40 PR = 6 : REM GOTTEM
50 PRINT OUT,IN,PR
60 PRINT "DONE!"