> doc.SerialSpt Title: Serial support module
Author: David De Vorchik
History:

        25-Mar-91 DDV Created.

Serial Device Support

This module provides the backwards compatibility section of the new device drivers, the module intercepts the related OS_Byte and OS_SerialOp calls and then converts them to new improved whiter than white calls to the actual device driver.

This has been done for two main reasons:

i) To keep backwards compatibility,
ii) To aid future writiers of serial device drivers.

The backwards compatibility has been kept as much as possible, although as under RISC OS 2.00 some areas are not fully handled, ie. using a certain sequence of OS_Bytes and OS_SerialOps can cause the system to get out of line.

The seperation was also performed to aid future developers of serial devier drivers, they need only worry about talking to the actual hardware rather than having to implement the code that convinces the machine that it is really a BBC model 'B' which part of the support module actually does.

Once installed the module hangs on SerialV and ByteV, through these are passed the calls to OS_SerialOp and OS_Byte. The kernel in RO2.50 will already change the calls to OS_Byte into suitable OS_SerialOps making the task a bit easier, although not all are handled.