| Routines

3501: THE 'NOT' FUNCTION (offset +30)

Used by the routine at compare. The address of this routine is found in the table of addresses. It is called via the calculator literal +30 by the routines at DRAW, int, sqr and to_power. It is also called indirectly via fp_calc_2. This subroutine returns a 'last value' of one if the present 'last value' is zero and zero otherwise. It is also used by other subroutines to 'jump on zero'.
Input
HL | Address of the first byte of the number
f_not | 3501 | CALL TEST_ZERO | The carry flag will be set only if the 'last value' is zero; this gives the correct result.
| 3504 | JR FP_0_1 | Jump forward.