Starting BXSND/BXRCV
Using BXSND/BXRCV over communications lines is identical to that described above for common media. The only difference is that a port name is given for the output file instead of the name of a disk file. Always start BXSND first. When prompted for an output file, enter a port name. This name will depend on which BASIC is being used. Typically "T1" or "T2". Consult the manual. If successful , BXSND prompts you to start the receiving program by running BXRCV on the other machine. When BXRCV asks for the input file name, enter the system name for that port (see below). After a few seconds delay, it should indicate which BASIC is sending the information and continue normally.
During communications, Xs may appear on the BXRCV screen while transfer progress is being displayed. These indicate a failed attempt that had to be retried and is a common occurrence. Occasionally, a number within parentheses amid several Xs may appear. This indicates that BXSND and BXRCV are transmitting in smaller chunks and occurs when too much data is being lost. If the numbers continue to get smaller, reaching one (1), and continue to appear in high concentrations, the transfer has probably failed. If the transfer fails completely, start the transfer again. Occasionally, BXSND and BXRCV can get out of sync.
Communication Port Names
When running BXRCV under MS-DOS, use the COM1 port as the communications port. Ensure the IBMCOM1.SYS driver provided with PRO/5 is used. This driver is loaded by MS-DOS at boot time, provided the appropriate line is in the config.sys file (see the MS-DOS manual). When PRO/5 asks for the name of the input port, enter "COM1".
When running PRO/5 under the UNIX operating system, use any of the terminal ports on the back of the computer as the communications port. The name given to BXRCV will resemble /dev/tty00 or /dev/tty01. Consult the system manuals for the names of the ports on your machine. Never use a PRO/5 terminal name such as "T1" or "T2". PRO/5 treats these names in a way that interferes with the data transfer. Also, ensure there is no other process accessing that port. Use the UNIX operating system ps -ae command to list any program, such as getty or sh, is using that port. Finally, ensure that the port is in raw mode to pass the requirements mentioned above. Because PRO/5 will access the port in whatever mode the port is in, ensure the port is conditioned before using BXRCV. An stty command is used to set the modes on any particular port (see the UNIX operating system manual). We have provided a script that will help, called "openport".