The following table summarizes the support for the two APIs in the various environments. For more details on what will and won't be supported by Carbon, read the Carbon Specification . SerialPortSample shows how to do this. On traditional Mac OS, Open Transport serial is layered on top of classic serial by a compatibility shim inside Open Transport. When deciding which serial API to use, you should take into account the following points.
Classic serial offers the best flexibility, performance and responsiveness.
If you have working code, there is no future compatibility benefit to be gained by moving it from classic serial to Open Transport serial, or vice versa. Open Transport's serial shim will then work with your driver automatically, and both Open Transport and classic serial clients will be able to use it. Regardless of the serial API you choose, you should be familiar with the information in Technote 1119, Serial Port Apocrypha . Inc. All rights reserved.