More and more, the parallel port is used to connect other devices than printers. To support this parallel port drivers are written for the devicesto work. This appendix presents devices for which parallel port support is written.

Chipset driver software for PCI Express Root Port device 9d14 With apologies if I'm in the wrong place for this question; a more obvious forum did not appear. After multiple searches I ran across some chipset driver software in a zip file ChipsetIntel10.1.zip. (Oddly, it came from a.ru site but was tested to be clean.) I.

To be clear: printers are not presented in this appendix as they are not supported by parallel port support projects.

Also, check the Linux Parallel Port support pages for more information here. Here you can find

• paride subsystem for parallel port IDE devices ( here)

• support for parallel port SCSI devices ( here)

29.1. Ethernet

• Accton EtherPocket adapter

• AT-Lan-Tec/RealTek parallel port ethernet adapter

• D-Link DE600/DE620 parallel port ethernet adapter

1. Calman Device Drivers Calman Display Calibration Software directly controls many hardware devices, including light meters, pattern sources, LUT processors, and display devices. The control interface to these devices may be USB, RS-232 serial, or wired or wireless network IP connections.
2. Once you know the manufacturer and model of the serial port, you should be able to find the driver for it. If at all possible, avoid third-party driver download sites. Look for the website of the device manufacturer.
3. Virtual COM Port Driver Installation Manual Installing the virtual COM port driver software on a computer makes possible CAT communication via a USB cable to the SCU-17 or an compatible transceivers. This will allow computer control of TX (PTT, KEY, FSK), and the audio In/Out interface (except the FT-891).

29.2. Hard drives

• H45 Quick HD

• KingByte IDE/ATAPI disks

• KT Technologies PHd portable hard disk

• MicroSolutions backpack hard-drives

• SyQuest EZ-135

• SyQuest EZ-230

• SyQuest SparQ

• ValueStor external hard-drive

29.3. Tape drives

• Hewlett-Packard Colorado Tracker 250 tape drive (all except the T1000e)

• Hewlett-Packard HP Colorado 5GB tape drive

• Iomega Ditto tape drive

• MicroSolutions backpack 8000t, 8000td tape drives

Drivers Autoland Port Devices Lucie

29.4. CD-ROM drives

Drivers Autoland Port Devices Terminal

• Freecom Power CD

• Freecom Traveller CD-ROM

• H45 Quick CD

• Hewlett-Packard HP 7100e/7200e CD-R

• KingByte IDE/ATAPI CD-ROMs

• MicroSolutions backpack CD-ROM. Models 163550 and later are supported by the paride driver. For models 160550 and 162550 seperate drivers are availavble.

• MicroSolutions backpack PD/CD drive

• SyQuest SyJet

29.5. Removable drives

• Avatar Shark 250

• Imation Superdisk

• Iomega ZIP, ZIP Plus drives

29.6. IDE Adapter

• Arista ParaDrive products

• DataStor Commuter disks

• Fidelity International Technologies TransDisk products

• Freecom IQ Cable Parallel

• Shuttle Technology EPAT/EPEZ parallel port IDE adapter

• Shuttle Technology EPIA parallel port IDE adapter

29.7. SCSI Adapters

• Adaptec APA-348 mini-SCSI plus adapter cable Driver available at here

• Adaptec APA-358 mini-SCSI EPP adapter cable Driver available at here

• Shuttle Technology EPSA-2 parallel port SCSI adapter Driver available at here

• Shuttle Technology EPST parallel port SCSI adapter Driver available at here

29.8. Digital Camera

• Connectix QuickCam

29.9. PCMCIA parallel port cards

The parport_cs driver requires kernel 2.2.x or later

• Quatech SPP-100

• IOtech DBK35, WBK20A

There are two completely different device drivers for the parallelport; which one you are using depends on your kernel version (whichyou can find out with the command uname -a). The driver changed in Linux 2.1.33; essentially allcurrent systems will be running kernel 2.2 or later, so you'llprobably want to skip ahead to the parport driver section.

A few details are the same for both styles of driver. Mostnotably, many people have found that Linux will not detect theirparallel port unless they disable 'Plug and Play' in their PC BIOS. (This is no surprise; the track record for PnP of non-PCI deviceswith Windows and elsewhere has been something of a disaster).

4.1. The lp device (kernels <=2.1.32)

The Linux kernel (<=2.1.32), assuming you have compiled in orloaded the lp device (the output of cat /proc/devices should include the device lp if it isloaded), provides one or more of /dev/lp0,/dev/lp1, and /dev/lp2.These are NOT assigned dynamically, rather, each corresponds to aspecific hardware I/O address. This means that your first printermay be lp0 or lp1depending on your hardware. Just try both.

A few users have reported that their bidirectional lp ports aren'tdetected if they use an older unidirectional printer cable. Checkthat you've got a decent cable.

One cannot run the plip and lp drivers at the same time on anygiven port (under 2.0, anyway). You can, however, have one or theother driver loaded at any given time either manually, or bykerneld with version 2.x (and later 1.3.x) kernels. By carefullysetting the interrupts and such, you can supposedly run plip onone port and lp on the other. One person did so by editing thedrivers; I eagerly await a success report of someone doing so withonly a clever command line.

There is a little utility called tunelp floating about with which you, as root, can tune theLinux 2.0 lp device's interrupt usage, polling rate, and otheroptions.

When the lp driver is built into the kernel, the kernel willaccept an lp= option to setinterrupts and io addresses:

Drivers Autoland Port Devices Inc

When loaded as a module, it is possible to specify io addressesand interrupt lines on the insmod command line (or in/etc/conf.modules so as to affect kerneld)using the usual module argument syntax. The parameters areio=port0,port1,port2 and irq=irq0,irq1,irq2. Read the man page forinsmod for more information on this.

**For those of you who can never find the standard portnumbers when you need them, they are as in the second exampleabove. The other port (lp0) is at 0x3bc.I've no idea what interrupt it usually uses.

The source code for the Linux 2.0 parallel port driver is in /usr/src/linux/drivers/char/lp.c.

4.2. The parport device (kernels >= 2.1.33)

Beginning with kernel 2.1.33 (and available as a patch for kernel2.0.30), the lp device is merely a client of the new parportdevice. The addition of the parport device corrects a number ofthe problems that plague the old lp device driver - it can sharethe port with other drivers, it dynamically assigns availableparallel ports to device numbers rather than enforcing a fixedcorrespondence between I/O addresses and port numbers, and soforth.

The advent of the parport device has enabled a whole flock of newparallel-port drivers for things like Zip drives, Backpack CD-ROMsand disks, and so forth. Some of these are also available inversions for 2.0 kernels; look around on the web.

The main difference that you will notice, so far as printing goes,is that parport-based kernels dynamically assign lp devices toparallel ports. So what was lp1 under Linux 2.0 may well be lp0under Linux 2.2. Be sure to check this if you upgrade from anlp-driver kernel to a parport-driver kernel.

The most popular problems with this device seems to stem frommisconfiguration:

The Distribution

Some GNU/Linux distributions don't ship with a properly setup /etc/modules.conf (or /etc/conf.modules), so the driver isn't loaded properly when you need it to be. With a recentmodutils, the proper magical lines from modules.conf seem to be:

The BIOS

Many PC BIOSes will make the parallel port into a Plug-and-Play device. This just adds needless complexity to aperfectly simple device that is nearly always present; turnoff the PnP setting for your parallel port ('LPT1' in manyBIOSes) if your parallel port isn't detected by the Linuxdriver. The correct setting is often called 'legacy', 'ISA',or '0x378', but probably not 'disabled'.

You can also read the parport documentation in your kernel sources, orlook at the parport website.

4.3. Serial devices

Serial devices are usually called something like/dev/ttyS1 under Linux. The utility stty will allow you to interactively view orset the settings for a serial port; setserial will allow you to control a fewextended attributes and configure IRQs and I/O addresses fornon-standard ports. Further discussion of serial ports underLinux may be found in the Serial-HOWTO.

When using a slow serial printer with flow control, you may findthat some of your print jobs get truncated. This may be due tothe serial port, whose default behavior is to purge anyuntransmitted characters from its buffer 30 seconds after the portdevice is closed. The buffer can hold up to 4096 characters, andif your printer uses flow control and is slow enough that it can'taccept all the data from the buffer within 30 seconds afterprinting software has closed the serial port, the tail end of thebuffer's contents will be lost. If the command cat file > /dev/ttyS2 produces completeprintouts for short files but truncated ones for longer files, youmay have this condition.

The 30 second interval can be adjusted through the 'closing_wait' command-line option of setserial (version2.12 and later). A machine's serial ports are usually initializedby a call to setserial in the rc.serial boot file. The call forthe printing serial port can be modified to set theclosing_wait at the same time as it sets that port's otherparameters.

4.4. USB Devices4.4.1. USB 1.1

Linux supports USB pretty well. USB should work with any late-model 2.2 kernel, and any 2.4 kernel or newer. Of course you need kernel support for USB, either linked in or through a module (recommended).

If you have a modular kernel, the following modules need to be loaded:

• usb-core.o

• usb-uhci.o or uhci.o or usb-ohci.o

• printer.o

Which one of usb-uhci.o or uhci.o or usb-ohci.o you need depends on the kind of motherboard or adaptor you have. Intel and Via motherboards and Via based adaptors are UHCI (you can use either usb-uhci.o or uhci.o). You can find out which type of HCI (Host Controller Interface) you have with lspci -v|grep HCI4.4.2. USB 2.0

Drivers Autoland Port Devices Gigabit

To get high speed transfers out of a USB 2.0 capable device you must attach it to an USB 2.0 controller and use the EHCI driver (ehci-hcd.o). A recent 2.4 kernel or higher is recommended if you want to use USB 2.0.

4.4.3. Hints

One thing to remember is that USB devices are dynamically allocated. A USB printer gets assigned a device file (/dev/usb/lp*) when it is turned on or connected. This could mean that print jobs are sent to the wrong printer because you turned them on in a certain order. CUPS uses special Uri's containing manufacturer, model and printer serial number to keep sending the jobs to the correct physical printer.

Although most USB printers work fine on Linux, there are exceptions. For example the new MF devices from Epson (Stylus CX3200/CX5200) return garbage when one polls the IEEE-1284 ID string via IOCTL, for example with the code of the CUPS 'usb' backend. Whereas one can poll the ID string via an Epson-proprietary method.

Till Kamppeter has written some tools to retrieve the device ID string from USB printers. getusbprinterid.pl and usb_id_test.c are the same thing but respectively in Perl and C. As mentioned above, the new MF devices from Epson are an exception, but the 'Epson proprietary method' is implemented in the ttink tool of the MTink package.

More documentation about USB is available at the Linux USB Website.