SPECIFYING THE PORT ADDRESS

If you tell MS-DOS Kermit to SET PORT COMn (where n is 1, 2, 3, or 4), and
Kermit responds:

  Warning, no hardware for this serial port.
  This port will be operated through the BIOS as BIOSn

it means that Kermit did not find an address for the port in the BIOS area or
it did find one but the hardware at that address did not look like a UART.  If
the cause of the message is a missing address, you can tell MS-DOS Kermit the
address of the port by issuing the following command:

  SET COMn \xhhhh

where n is 1, 2, 3, or 4, and hhhh are four hexadecimal digits (0-9, A-F)
representing the 16-bit address.  This command not only informs Kermit of the
address, but also inserts the address into the BIOS so other programs can find
the port (if they follow the rules), and so you don't have to give this
command to Kermit again until after the next time you reboot.

After giving the SET COMn command, give a SET PORT COMn command for the same
port, e.g.:

  set com3 \x3f8   ; FIRST specify the address of COM3 
  set port com3	   ; THEN select COM3

How do you know what addresses to give?	 If have purchased an internal modem
or an add-on serial port, the installation instructions should tell you.  The
device must be configured -- generally by setting little switches or
installing or removing jumpers.	 You have to make sure that the address that
you have chosen agrees with the address that Kermit will use.

Although it is not recommended that you guess at address values, sometimes it
is the only way (as often with inherited equipment), for which occasions here
is a list of the addresses commonly used for serial ports and internal modems:

  Port	 Likely Addresses (hexadecimal)
  COM1	     03F8
  COM2	     02F8
  COM3	     03E8, 3220 (PS/2)
  COM4	     02E8, 3228 (PS/2), 02E0

You probably won't find a serial port at any address not listed above, but you
might find a port at another port's expected address.  The use of these
addresses in SET COMn commands should be relatively harmless (provided you
don't also specify an interrupt, explained later); if there is no error
message, Kermit found a possibly usable port. If there is an error message, no
harm should have been done.

Now let's look at the other cause for the "This port will be operated through
the BIOS" message, namely that an address was found in segment 40, but the
device at that address does not appear to be a genuine serial port.
Explanations might include:

 1. The device is at a different address.  Check your device's configuration
    again, or else your SET COMn command.

 2. Your device is indeed at the given address, but its registers do not
    contain values expected of a true PC serial port.  In that case, BIOS
    operation is the only alternative.

 3. Your device is at the given address, but there is a conflict with another
    device at that address or the machine's bus speed (not CPU speed) is set 
    so high that the hardware test gave confusing results.

When Kermit operates a port through the BIOS, rather than directly, it will be
MUCH slower and might not work at all because the BIOS requires the CD, CTS,
and DSR modem signals to be asserted by the device connected to the port (and
the CD signal is normally NOT asserted by a modem before it has made a
connection to another modem).  In that case, you will have to configure the
device (e.g. modem) to assert DSR, CTS, and CD always, or wire your modem
cable to fake these signals (e.g. by connecting CD and DSR together).

Assuming you have found the right address for your COM3 or COM4 port (or
nonstandard address for COM1 or COM2), and you want these addresses to be set
correctly for Kermit at all times, even if it doesn't read its initialization
file, you can put a command like the following in your AUTOEXEC.BAT file:

  set kermit=com3 \x3e8; com4 \x2e8;

.