Sorry for the confusion
CY ,AC ,OV were user defined functions that has the format
In VB [Name(State as Boolean)] equal in C to [void name(Bool state);]

I wrote these functions to set the correct bits in PSW in the simulator.

So if I want to set the OV flag
In VB [OV(True)] equal in C to [OV(1);]

Can you give me a mathematical algorithm to perform the ADD,ADDC,SUBB functions in C or Visual Basic including Altering of the state flags ?

My current definition for ADD function is this (in VB)

Public Function ADD8(ByVal Op1 As Byte, ByVal Op2 As Byte, Optional ByVal Op3 As Byte = 0) As Byte
Dim i As Integer
i = CInt(Op1) + CInt(Op2) + CInt(Op3)

ADD8 = LOW8(i)

AC (LOW4(Op1) + LOW4(Op2) + Op3) > 15
CY i > &HFF
OV (i > &HFF) Xor (((Op1 And &H7F) + (Op2 And &H7F) + Op3) > &H7F)


End Function

SFR is a structure that hold individual register values
To perform ADD A,R0

SFR.ACC=ADD8(SFR.ACC,SFR.R0)

To perform ADDC A,R0

GetCarry() is also a user defined function that returns the state of the carry flag as 1 or 0
SFR.ACC=ADD8(SFR.ACC,SFR.R0,GetCarry());

Also in vb the Hex notation is different
&HFF is equal in c to FFh
&H7F is equal in c to 7Fh

I hope this information will give you a clear view.

Thank you!