Dell OptiPlex E1 - Manual (Page 19)

Mouse Port enables or disables the system's built-in Personal System/2 (PS/2) -compatible mouse port. Disabling the mouse
allows an expansion card to use interrupt request (IRQ) 12.
For more information about built-in ports, port designations, IRQs, and the remapping of ports, see "Connecting External Devices"
in your online System User's Guide.
Serial Port 1 and Serial Port 2
Serial Port 1 and Serial Port 2 configure the system's built-in serial ports. These categories can be set to Auto (the default option)
to automatically configure a port, to a particular designation (COM1 or COM3 for Serial Port 1; COM2 or COM4 for Serial Port 2),
or to Off to disable the port.
If you set a serial port to Auto and add an expansion card containing a port configured to the same designation, the system
automatically remaps the built-in port to the next available port designation that shares the same IRQ setting as follows:
COM1 (input/output [I/O] address 3F8h), which shares IRQ4 with COM3, is remapped to COM3 (I/O address 3E8h).
Likewise, COM2 (I/O address 2F8h), which shares IRQ3 with COM4, is remapped to COM4 (I/O address 2E8h).
NOTES: When two COM ports share an IRQ setting, you can use either port as necessary, but you may not be able to
use them both at the same time. If the second port (COM3 or COM4) is also in use, the built-in port is turned off.
If you are using the Microsoft Windows 95 or IBM OS/2 operating system, you cannot use both serial ports at the same
time.
For more information about built-in ports, port designations, IRQs, and the remapping of ports, see "Connecting External Devices"
in your online System User's Guide.
Parallel Port
Parallel Port configures the system's built-in parallel port. This category can be set to 378h (the default setting), to alternate
addresses 278h or 3BCh, or to Off to disable the port.
NOTE: Do not set Parallel Port to 278h if you have an Enhanced Capabilities Port (ECP) device connected to the port.
Parallel Port Mode
Parallel Port Mode controls whether the system's built-in parallel port acts as an AT-compatible (unidirectional) or PS/2-compatible
(bidirectional) port.
Your system also supports ECP mode, which can be used by Windows 95. Windows 95 uses ECP protocol automatically if it
detects an ECP-capable device, eliminating the need for an ECP option in this category.
Set this category according to the type of peripheral device connected to the parallel port. To determine the correct mode to use,
see the documentation that came with the device.
IDE Drive Interface
IDE Drive Interface enables or disables the system's built-in EIDE hard-disk drive interface.