Specifications

Software Configuration
3–7
Port Address
Serial 1 3F8h – 3FFh
Serial 2 2F8h – 2FFh
Serial 3 3E8h – 3EFh
Serial 4 2E8h – 2EFh
Table 3-2 Serial Port I/O Addresses
COMn is a logical designation, not a physical value. When the system boots, the ROM BIOS scans the
standard serial port addresses and installs the first port it finds as COM1. If it finds a second port, it
installs that one as COM2, and so on. If you disable a serial port, the COMn designations change.
3.4.3 Parallel Port
No special configuration is required to use the system with a PC-compatible parallel printer. SETUP
allows you to enable the parallel port as the primary, or secondary port, or to disable it entirely.
The ROM BIOS assigns a logical designation (LPT1 or 2) to the parallel port, based on a scan at boot
time. Changing the port’s designation to Secondary with SETUP does not necessarily change it from
LPT1 to LPT2. There must be an LPT1 elsewhere in the system for the onboard parallel port to become
LPT2.
3.4.4 Floppy Interface Enable
Enable or disable the onboard floppy interface. When disabled, the I/O ports assigned to the floppy
controller become available, allowing them to be used by other devices installed on the expansion bus.
3.4.5 IDE Interface Enable
Enable or disable the onboard IDE hard disk interface. When disabled, the I/O ports and IRQ assigned to
the IDE controller become available, allowing them to be used by other devices installed on the expansion
bus.
3.4.6 Hot Key Setup Enable
In some embedded systems, you do not want an end-user to use the hot-key sequence (CTRL-ALT-ESC)
to enter SETUP. You can enable or disable hot-key access to SETUP with this parameter. (This also
prevents “+++” from entering SETUP when using the serial console feature.)
3.4.7 Video State
You can set this option to Enable or Inhibited. Inhibited blanks the display until your program makes a
call to the Video Restore State function in the video BIOS (via INT10h). This provides a means of
controlling what appears on the screen when the system starts up. This option can be used to inhibit the
POST test display and everything else that DOS or an application would display, until a call is made to
the video BIOS.
The following is an example of code that reenables the display inhibited by this option: