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Length: 1280 (0x500)
Types: TextFile
Names: »ADDSUB.SRC«
└─⟦c9df7130d⟧ Bits:30005915 Pascal MT+ Release 5.2 (Jet-80)
└─ ⟦this⟧ »ADDSUB.SRC«
; Decimal byte add/subtract procedures for fixed point package ; function addbyte( var carry: carrtyp; a, b: byte ): byte; external; entry addbyte addbyte pop h ; hl := return address pop b ; b := first operand, c := second operand inx s ; Skip over length byte. pop d ; de := address of the carry flag ldax d ; a := carry flag cpi 1 cmc ; carry := not carry mov a,b adc c ; a := a + c + carry daa mov b,a mvi a,0 jrnc NoCarry ; Branch if carry = 0 mvi a,1 NoCarry stax d ; Set passed carry flag to correct value. xra a mov d,a mov e,b pchl entry subbyte subbyte pop h pop b ; b := first operand, c := second operand inx s ; Skip over length byte. pop d ; de := address of the carry flag ldax d ; a := carry flag cpi 1 cmc ; carry := not carry mov a,b sbb c ; a := a - c - carry daa mov b,a mvi a,0 jrnc NoCar ; Branch if carry = 0 mvi a,1 NoCar stax d ; Set passed carry flag to correct value. xra a mov d,a mov e,b pchl «eof»