Contents:
This section contains technical information
suitable for Developers and System Administrators.
Configuring
ISA Boards in EISA Machines
When installing ISA boards in an EISA machine
it is recommended to use the system's EISA Configuration Utility. Hardware
conflicts can easily be detected and resolved using this method.
If ISA boards only are being installed,
and they are not being configured, proceed to step 5.
The Driver diskette contains configuration
files required by EISA machines to configure EISA and ISA boards.
Configure your EISA machine to recognise
the installed board(s) using the respective system configuration utility.
Consult your computer system installation manual for instructions on
using the system configuration utility.
Follow these steps to reconfigure your EISA
machine:
Step 1.
Power-on and boot-up your machine using the diskette containing the
system configuration utility supplied with your machine.
Step 2.
If you are not using a working copy of this reference diskette, then
make a working copy using the system configuration utility. Restart
the machine from the working copy.
Step 3.
Use the system configuration utility to copy the appropriate configuration
file from the root directory of the distribution diskette. The configuration
file is !STL0200.CFG - EISA configuration file for EasyIO (ISA).
Step 4.
Save the new configuration and exit the utility.
Step 5.
Upon reboot to the system configuration utility, the configuration
file information will be updated and a valid I/O address will be selected
automatically from the choices available.
Step 6.
Save the new configuration, exit the system configuration utility,
and reboot your system.
Interfaces to the
Multiport Board
There are three interfaces by which applications
can access the serial ports on Stallion multiport boards: the Command-line,
DOS INT21h and BIOS INT14h interfaces. All of the interfaces are standard
interfaces to devices in the DOS world. It should be noted, however,
that not all DOS applications abide by these interfaces and, for reasons
of their own, use direct hardware access to the native serial ports.
These applications cannot be used in conjunction with Stallion I/O boards.
Applications that use the standard DOS interfaces
with Stallion Technologies ports have the additional benefit over native
ports of emplying the buffering and handshaking facilities provided
by the Stallion multiport boards. These facilities are value-added
by the DOS Driver, and are not available in the standard INT21h or INT14h
interfaces.
Additionally, some models of EasyIO process
DSR signals. To be compatible with DOS interfaces, no data is allowed
to be transmitted unless DSR is asserted.
Command-Line Interface
Stallion ports are extensions to the standard
DOS file system and so follow on consecutively from existing native
ports in the device name hierarchy. That is, the ports on an EasyIO4
in a DOS machine with COM1: and COM2: installed will be numbered as
COM3: TO COM6: (unless alternate port naming convention is used).
From the DOS command-line Stallion ports can
be accessed as you would access any other file. For example you may
use pipes with these devices to redirect input and output from them,
eg. type \autoexec.bat
> com5: Or you may use the COPY command to do the
same thing, eg. copy
\autoexec.bat com5:
You can also switch your standard input and
output from the console to any Stallion Technologies port with a terminal
configured. The terminal should be configured to match the line settings
of the Stallion port to be used. The following command will switch the
standard input/output to the terminal on COM3:
ctty com3:
This allows you to type commands and receive
their output on the terminal device. This command (typed at the terminal's
keyboard) will return standard input/output to the system console.
ctty con:
Note, however, that not all applications
abide by the DOS device interface and so, even though you may enter
input at the terminal's keyboard, the results may still be displayed
on the system console. In this case the application uses direct hardware
access to display its output. Stallion port users should avoid the DOS
MODE command. The DOS MODE command is not compatible with Stallion ports.
The serial device configuration functions of this command are replaced
for Stallion Technologies ports with those of the program ATAMODE.EXE.
Modifying Port Signals
The DSR Signal.
If DSR is not asserted, then data will be prevented from being transmitted
on a port.
The ATAMODE.EXE program, using the '-d' option
allows you to report the DSR signal as always high, on any or
all ports if required. This is required if you do not wish to wire the
cable to assert DSR.
To set DSR to report high always on com5, use:
atamode -d com5:1
To set DSR reporting back to normal on com5:
atamode -d com5:0
Warning: DSR signals should not
be enabled on board types that do not support it as it may adversely
affect the performance of the driver.
DTR and RTS Signals.
The DOS native serial device driver asserts DTR and RTS before each
character is sent. For Stallion ports the DTR and RTS lines are asserted
in the driver initialization routine and will remain asserted unless
they are deliberately cleared. If you wish, you may use the ATAMODE.EXE
program to raise or lower DTR and/or RTS for any port. The format of
the command required is: atamode
-h COM#:rts,dtr
For example to raise DTR and lower RTS on Stallion
port COM3: you would execute the following command: atamode
-h COM3:0,1
INT21h Interface
The INT21h interface presented by the DOS Driver
conforms to that specified by the IBM 'Disk Operating System Technical
Reference'. The DOS INT21h interface permits filesystem operations such
as open(), close(), read() and write() upon ports as they appear just
as files under DOS. For the application programmer it is simply a matter
of using these routines with Stallion Technologies serial devices as
you would to manage native serial devices such as COM1:. Stallion
serial devices can be used with any application that communicates with
serial devices via the DOS filesystem interface.
Applications programmers should note that the
standard INT21h interface does not provide a means to configure ports
for operation, and whereas BIOS INT14h does allow you to configure ports,
the upper limits for the parameters are restrictive eg. a maximum baud
rate of 9600. To bypass these limitations, the utility ATAMODE.EXE can
be used to modify the coms parameters of selected ports.
INT14h Interface
The BIOS INT14h interface conforms to that specified
in the IBM 'Personal Computer Hardware Reference Library'. The INT14h
vector is intercepted by the DOS Driver and the request processed according
to the targeted port. If the targeted port is not one of the Stallion
ports then the driver relinquishes the request to the next driver in
the INT14h interrupt chain.
The most common interfaces used by comms applications
are the Fossil and Digiboard INT14h interfaces, which are both supported
by the Stallion DOS driver.
Modifying
the BIOS Hardware Configuration
Some DOS programs use the BIOS hardware configuration
to determine the number of serial ports in your machine. As a result,
the program may not allow you to use a Stallion port as it recognises
the last COM port to be COM2 (or COM1, depending on the number of native
serial ports you have installed).
A work-around for this problem has been provided
using the ATAMODE.EXE program. This allows you to set the number of
RS232 ports found by BIOS to be any number between 1 and 7. Note that
this number should include native serial ports that are already installed.
For example, if you have a machine with 2 native serial ports and wish
to have BIOS recognize up to 4 Stallion ports (ie. COM3 to COM6) you
would call ATAMODE.EXE with the '-p' option as follows: atamode
-d 6
The upper limit of 7 serial devices is a restriction
of the BIOS data area as the space set aside for serial ports is only
3 bits. Of course, reinstating the original BIOS value can be accomplished
using ATAMODE.EXE. Regardless of whether you reset the value yourself,
the BIOS will reset this value itself when the machine is next restarted.
If you wish to permanently run your system with this modification, you
should place the appropriate ATAMODE.EXE in your AUTOEXEC.BAT file.
Warning: The BIOS data area
is accessible to, and employed by, many varying DOS applications to
determine the serial hardware configured in the system. Users who wish
to modify the data area should be aware that some applications communicate
directly with the serial device hardware and these applications fail
when attempting to access the hardware of Stallion ports. It is not
possible to access Stallion ports under DOS other than through the interfaces
provided by the DOS Driver product. If you wish to use the ports with
a particular application, please ensure that the application conforms
to either the DOS INT21h or BIOS INT14h interfaces
