frmThunkCalc ThunkCalc Form1 Frame1 Choose DLL opt32 Use 32 bit DLL opt16 Use 16 bit DLL Label1 16 ->32 bit Thunk operator System operator System operator System operator System txVal2 txVal1 labReadOut Text3_Change Text1_Change arg1E Text1 Text2_ChangeZ Text2n operator_Clickb index Numbers lpVBArrayC VBPTRtoLongP VBSel lhvbarrayZ GlobalHandle hvbArray VBLowWord GlobalFixP OpFlag SumArray SubTwo32z MultTwo32 DivTwo32 GlobalUnFix Readout Caption NumOps; LastInput Operator Form_Load [0 to 3] answer AddTwo32 Option1_Click Frame1_DragDropU Source Control option1 Opt16bit Value AddTwo SubTwo MultTwo DivTwo txVal1 txVal1_Change= txVal2_Change txVal2 Label1_Click Opt16bit_Click opt32_Click ReadOut_Click labReadOut_Click labReadOut opt16, Form_Load operator_Click first must get the pointer (selector/offset) get selector from pointerm get handle from selector lock VB array in virtual address space Can't divide by zero ThunkCalc txVal1_Change txVal2_Change