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346A: THE 'ABSOLUTE MAGNITUDE' FUNCTION (offset +2A)
The address of this routine is found in the table of addresses. It is called via the calculator literal +2A by the routines at CIRCLE, DRAW, CD_PRMS1, PRINT_FP, get_argt and cos. It is also called indirectly via fp_calc_2.
This subroutine performs its unary operation by ensuring that the sign bit of a floating-point number is reset.
'Small integers' have to be treated separately. Most of the work is shared with the 'unary minus' operation.
Input
HL Address of the first byte of the number
Output
abs 346A LD B,$FF B is set to +FF.
346C JR NEG_TEST The jump is made into 'unary minus'.
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