' Program Listing 42.2
Public Sub ProcessInput()
  Dim hiData As String
  Dim loData As String
  Dim tempC As Single
  Dim rawNeg As Integer
  
  hiData = Mid$(buffer, 5, 2)
  loData = Mid$(buffer, 7)
  
  If hiData = "00" Then ' positive temp
    tempC = CSng(HexToDec(loData)) / 2
  Else ' negative temp
    ' two's compliment
    rawNeg = (HexToDec(loData) Xor 255) + 1
    tempC = CSng(rawNeg) / -2
  End If
  
  ' display
  lblTempC.Caption = Format(tempC, "##0.0°C")
  lblTempF.Caption = Format(tempC * 9# / 5# + 32#, "##0.0°F")
End Sub