| Routines

2C88: THE 'ALPHANUM' SUBROUTINE

Used by the routines at S_ALPHNUM, LOOK_VARS and LET. This subroutine returns with the carry flag set if the present value of the A register denotes a valid digit or letter.
Input
A | Character code
Output
F | Carry flag set if the character is alphanumeric
ALPHANUM | 2C88 | CALL NUMERIC | Test for a digit; carry will be reset for a digit.
| 2C8B | CCF | Complement the carry flag.
| 2C8C | RET C | Return if a digit; otherwise continue on into ALPHA.