| Routines

11547: THE 'NUMERIC' SUBROUTINE

Used by the routines at OUT_SP_2, ALPHANUM, DEC_TO_FP and STK_DIGIT. This subroutine returns with the carry flag reset if the present value of the A register denotes a valid digit.
Input
A | Character code
Output
F | Carry flag reset if the character is a digit (0-9)
NUMERIC | 11547 | CP "0" | Test against 48, the code for '0'.
| 11549 | RET C | Return if not a valid character code.
| 11550 | CP 58 | Test against the upper limit.
| 11552 | CCF | Complement the carry flag.
| 11553 | RET | Finished.