Serial Port Routines for the BX24

These routines were developed by Nick Taylor. A brief description appears below. For the complete file in zipped format click here.

'=====  SerialPort_24.BAS  =================================== BX-24 ==
' 1999/11/02 - Modified from NetMedia's SerialPort.bas to support the BX-24's
'   Com1 and Com3 by Nick Taylor -
Option Explicit
' This module is used to transfer data to and from both serial ports.  Note
' that the queue size must be 9 bytes larger than the largest data element to
' provide space for the queue pointers.
' Com1: TxD = pin-1, RxD = pin-2
' Com3: user defined pins
' Com3 may be used to support serial I/O on any of the BX-24's 19 I/O pins.  
' To  support more than one serial device with Com3 it is necessary to 
' call DefineCom3 to move Com3 to the desired I/O pins (and to call OpenCom 
' if a different baud rate or different buffers are needed) prior to 
' commmunicating with each device.  Use OpenSerialPort_X to initially open 
' a Com3 port, and then use ReOpenSerialPort_X each time that port needs to 
' be reopened.
' This implementation of SerialPort_24 supports only two additional serial
' ports, each with its own buffers.  To add more ports it is only necessary 
' to copy the needed _x routines and replace the _x with _y.
' Note that _4 is fully implemented, but _3 has only PutByte and GetByte at 
' this time.  Unused routines are NOT compiled and do not add to the 
' resulting code size.