Specifications

3 - 7

Note

The "COMn" (n=1,2) designation is a logical value, not a

physical value. During the system boot sequence, the ROM-

BIOS scans both sets of serial port addresses, and installs the

first serial port it locates as the COM1 device, and the second,

if found, as COM2. Therefore, if you disable the board's

primary serial port, the secondary port will become "COM1",

not "COM2"! There must be COM1 (primary serial port)

device elsewhere in the system for the onboard secondary

serial port to be accessed as COM2.

In addition, each port's baud rate and data characteristics must be initialized to match the

requirements of the external devices that will be connected. One way to set (and alter) either serial

port's baud rate and data characteristics is by means of the DOS MODE command. Here is how

you might use the MODE command to initialize the COM1 port to 9600 baud, no parity, 8 data

bits, and 1 stop bit:

MODE COM1:9600,n,8,1

In many cases it is not necessary to use a mode command, because the software which will operate

the serial port will initialize the port when it loads.

3.5.2 Serial Console Option

In many embedded applications it is desirable to substitute an RS232C serial device (terminal,

remote computer, or other serial device) for the video controller, monitor, and keyboard normally

used as the PC console device. The serial console device can be connected to the board's primary

or secondary serial port; the Ampro ROM-BIOS contains support for serial input and serial output.

Serial console support parameters are stored in the board's Configuration Memory and are

controlled by the SETUP function, which is used to install the required console support.

SETUP parameters provide support for serial console input, such as a serial keyboard or modem,

and serial console output, such as a serial display terminal or remote computer. Additionally, a

standard AT keyboard can be combined with a serial display, or serial input can be used with a

standard video display.

Caution

Be careful when changing the console configuration using

SETUP. It is possible to specify "none" for console input and

output, in which case there will be no console access to the

system.