Adding serial and parallel ports

About serial ports

For ISA and EISA buses:

support for a single-port ``dumb'' (or ``non-intelligent'') serial card on COM1 and COM2 is configured into the kernel by default. A single-port serial I/O card on COM1 will work as expected with an SCO OpenServer system provided it conforms to the standard IBM specification.

The serial driver in SCO OpenServer allows ISA serial ports on COM1 to use IRQ 4, and ISA serial ports on COM2 to use IRQ 3. Unlike the standard IBM interrupt scheme, however, the serial driver does not allow serial ports on COM3 or COM4 to share interrupt vectors with COM1 or COM2, and it does not support polling.

The serial driver in SCO OpenServer does support several serial cards that can use IRQs other than 4 and 3 on COM3 and COM4. You may be able to adjust serial card settings to change the IRQ and base I/O address. See the documentation provided with the card for more information. See ``ISA and EISA serial cards'' for more information.

For the MCA bus:

the serial driver only supports cards on ports COM1 and COM2. See ``Micro Channel Architecture serial cards'' for more information.

For the PCI bus:

the serial driver supports a default of four single and multiport cards on ports COM1 through COM4. PCI serial cards are autodetected at boot-time, however, corresponding device nodes are not created until you run the Serial Manager or mkdev serial. See ``PCI serial cards'' for more information.

The ways in which you can combine dumb single port and multiport serial cards is limited by the minor numbering scheme of the devices. See ``Combining single port and multiport serial cards'' for details.

NOTE: Before adding a single-port serial card or a multiport expansion card, determine whether the card is a ``smart'' (or ``intelligent'') serial card or a SCO OpenServer-supported dumb serial card. If it is a smart card (such as the Arnet Smartport), the manufacturer will have supplied installation software and a driver. This should be all you need to add the card to an SCO OpenServer system. Follow the instructions provided with your card, referring to your computer hardware manual if necessary.

Some vendor-supplied drivers may not print a recognition message at system startup.

Different models of multiport dumb serial I/O adapters have unique hardware settings; SCO OpenServer systems provide hardware-specific driver code for each card that is supported. Only cards with status poll registers can work with the high-performance driver scheme chosen, and new cards require additional driver support.

If your system does not report the configuration of a serial card correctly at system startup, the card may not be configured correctly. Check the card's hardware documentation for the proper settings.

NOTE: An error message such as ``cannot create'' or ``cannot open'' is displayed if you attempt to access a serial port that is not physically installed and defined.