Spectrum ROM: Routine at 11554

11554: THE 'STK-DIGIT' SUBROUTINE

Used by the routines at DEC_TO_FP and INT_TO_FP.

This subroutine simply returns if the current value held in the A register does not represent a digit but if it does then the floating-point form for the digit becomes the 'last value' on the calculator stack.

Input
A	Character code

Output
F	Carry flag reset if the character is a digit (0-9)

STK_DIGIT

11554

CALL NUMERIC

Is the character a digit?

11557

RET C

Return if not.

11558

SUB "0"

Replace the code by the actual digit.

This routine continues into STACK_A.