linux/Documentation/ez.txt (c) 1996 Grant R. Guenther This file documents the ez driver for the parallel port versions of SyQuest's EZ135 and EZ230 removable media disk drives. Special thanks go to Pedro Soria-Rodriguez for his help testing the EZFlyer 230 support. The drive is actually SyQuest's IDE product with a ShuttleTech IDE <-> parallel converter chip built in. Before attempting to access the new driver, you will need to create some device special files. The following commands will do that for you: mknod /dev/eza b 40 0 mknod /dev/eza1 b 40 1 mknod /dev/eza2 b 40 2 mknod /dev/eza3 b 40 3 mknod /dev/eza4 b 40 4 chown root:disk /dev/ez* chmod 660 /dev/ez* You can make devices for more partitions (up to 15) if you need to. You can alter certain driver parameters on the LILO or LOADLIN command line. The general syntax is ez=base[,irq] where base is the base address of the parallel port you want to use and irq is the interrupt number for that port. By default, the driver uses the ports at 0x378 and irq 7. You can disable the interrupt by specifying it as 0. For example, to run the driver on port 0x3bc without an interrupt, you would append the following to the LILO command line: ez=0x3bc,0 If you have configured the driver as a loadable module, you can adjust these parameters on the insmod command line using the variables ez_base and ez_irq. For example: insmod ez ez_base=0x3bc The driver can detect if the parallel port supports 8-bit transfers. If so, it will use them. The driver can be used with or without interrupts. If an IRQ is specified the driver will use it - if it can. If the irq number is set to 0, an alternative, polling-based, strategy will be used. Polling consumes more CPU time, but may be more stable on some systems. If you experience timeout errors while using this driver - and you have enabled interrupts - try disabling the interrupt. I have heard reports of some parallel ports having exceptionally unreliable interrupts. This could happen on misconfigured systems in which an inactive sound card shares the same IRQ with the parallel port. (Remember that most people do not use the parallel port interrupt for printing.) It would be advantageous to use multiple mode transfers, but ShuttleTech's driver does not appear to use them, so I'm not sure that the converter can handle it. It is not currently possible to connect a printer to the chained port on an EZ drive and expect Linux to use both devices at once. If you need to do this, build both the ez and lp drivers as modules and load one or the other as required. When the EZ230 powers on, the "standby timer" is set to about 6 minutes: if the drive is idle for that length of time, it will put itself into a low power standby mode. It takes a couple of seconds for the drive to come out of standby mode. So, if you load this driver while it is in standby mode, you will notice a "freeze" of a second or two as the driver waits for the EZ230 to come back to life. Once loaded, this driver disables the standby timer (until you next power up the EZ230 ...) Keep an eye on http://www.torque.net/ez135.html for news and other information about the driver. If you have any problems with this driver, please send me, grant@torque.net, some mail directly before posting into the newsgroups or mailing lists.