--- name: "intro" section: "4" platform: "openbsd" package: "man" version: "8.0-current-20261101" release: "OpenBSD 8.0-current (2026-11-01)" platforms: ["linux", "freebsd", "openbsd"] url: "https://new.carta.tech/intro/4" --- # intro(4) introduction to special files and hardware support ## NAME **intro** – introduction to special files and hardware support ## DESCRIPTION The manual pages in section 4 describe the special files, related driver functions, and networking support available in the system. In this part of the manual, the SYNOPSIS section of each configurable device gives a sample specification for use in constructing a system description for the [config(8)](/config/8.md) program. The DIAGNOSTICS section lists messages which may appear on the console and/or in the system error log */var/log/messages* due to errors in device operation; see [syslogd(8)](/syslogd/8.md) for more information. This section contains both devices which may be configured into the system and network related information. The networking support is introduced in [netintro(4)](/netintro/4.md). ## DEVICE SUPPORT This section describes the hardware supported on the Alpha platform. Software support for these devices comes in two forms. A hardware device may be supported with a character or block *device* *driver*, or it may be used within the networking subsystem and have a *network* *interface* *driver*. Block and character devices are accessed through files in the file system of a special type; see [mknod(8)](/mknod/8.md). Network interfaces are indirectly accessed through the interprocess communication facilities provided by the system; see [socket(2)](/socket/2.md). A hardware device is identified to the system at configuration time and the appropriate device or network interface driver is then compiled into the system. When the resultant system is booted, the autoconfiguration facilities in the system probe for the device and, if found, enable the software support for it. If a device does not respond at autoconfiguration time, it is not accessible at any time afterwards. To enable a device which did not autoconfigure, the system will have to be rebooted. The autoconfiguration system is described in [autoconf(4)](/autoconf/4.md). A list of the supported hardware and devices is given below. ## SUPPORTED SYSTEMS DEC and Compaq have produced a series of the Alpha CPU, some of which are listed below, along with some systems which contain them. "EV" stands for "Extended VAX"( or "Electro Vlassic") and the number following is a reference to the CMOS process used to make the chips. "LCA" stands for Low Cost Alpha, and "PCA" stands for PC-architecture Alpha. - 21064 **EV4**( 100-200 MHz, 0.75 micron) AlphaPC 64 (EB64) - Avanti family Digital's lower-end PCI-based workstations. AlphaStation 200 4/100-166 (Mustang)\ AlphaStation 400 4/166 (Chinet) - Pelican family Low-end TURBOchannel based workstations. DEC 3000/300 (150 MHz) (Pelican)\ DEC 3000/300X (175 MHz) (Pelican+)\ DEC 3000/300L (100 MHz) (Pelica)\ DEC 3000/300LX (125 MHz) (Pelica+) - Sandpiper family High-end TURBOchannel based workstations. DEC 3000/400 (133 MHz) (Sandpiper)\ DEC 3000/600 (175 MHz) (Sandpiper+) - Flamingo family High-end TURBOchannel based workstations. DEC 3000/500 (150 MHz) (Flamingo)\ DEC 3000/500X (200 MHz) (Hot Pink)\ DEC 3000/800 (200 MHz) (Flamingo II) - 21064-A **EV45**( 225-333 MHz, 0.50 micron) DEC 3000/700 (225 MHz) (Sandpiper45)\ DEC 3000/900 (275 MHz) (Flamingo45) - Avanti family Digital's lower-end PCI-based workstations. AlphaStation 200 4/233 (Mustang+)\ AlphaStation 205 4/133-333 (LX3)\ AlphaStation 250 4/300 (M3+)\ AlphaStation 255 4/133-333 (LX3+)\ AlphaStation 300 4/266 (Melmac)\ AlphaStation 400 4/233-300 (Avanti) - 21066 **LCA4**( 166-233 MHz, 0.75 micron) - NoName family Digital's lowest-end family of PCI-based systems. DEC AXPpci33 (NoName)\ Universal Desktop Box AXPpci166MT (UDB/Multia) 21066 evaluation motherboard (EB66) - 21066-A **LCA45**( 233 MHz, 0.50 micron) 21066-A evaluation motherboard (EB66+) - 21068 **LCA4s**( 66-233 MHz, 0.75 micron) Universal Desktop Box AXPpci233MT (UDB/Multia) - 21164 **EV5**( 250-366 MHz, 0.50 micron) - Mikasa family AlphaServer 1000 5/300 (Pinnacle) - Noritake family AlphaServer 1000A 5/300 (Pinnacle) 21164 evaluation motherboard (EB164) - 21164-A **EV56**( 400-766 MHz, 0.35 micron, BWX) - Personal Workstation (PWS) PWS 433a/433au (Miata)\ PWS 500a/500au (Miata)\ PWS 600a/600au (Miata) - Mikasa family AlphaServer 1000 5/333-500 (Primo) - Noritake family AlphaServer 1000A 5/333-500 (Primo)\ AlphaServer 800 5/333-500 (Corelle) - EB164 family AlphaPC 164 motherboard (EB164)\ AlphaPC 164LX motherboard (EB164) DigitalServer 3300( rebadged AlphaServer 800 for NT) - 21164-PC **PCA56**( 400-600 MHz, 0.35 micron, MVI, no L2 cache) AlphaPC 164SX motherboard (EB164) PWS 466au (Miata)\ PWS 550au (Miata) - 21264 **EV6**( 450-600 MHz, 0.35 micron) APi UP1000 and UP1100; AMD 751-based EV6 systems. 264DP, XP1000, DS10, DS20 Tsunami-based systems. - 21264-A **EV67**( 600-833 MHz, 0.28 micron) ## LIST OF DEVICES A complete list of available devices is contained within the pages describing the system buses and controllers. For example, a PCI device would be listed in the [pci(4)](/pci/4.md) man page. The following buses and controllers list these devices: - [eisa(4)](/eisa/4.md) introduction to EISA bus support - [iic(4)](/iic/4.md) Inter IC (I2C) bus - [isa(4)](/isa/4.md) introduction to ISA bus support - [onewire(4)](/onewire/4.md) 1-Wire bus - [pci(4)](/pci/4.md) introduction to PCI bus support - [usb(4)](/usb/4.md) introduction to Universal Serial Bus support ## SEE ALSO [autoconf(4)](/autoconf/4.md), [config(8)](/config/8.md) ## HISTORY The Alpha **intro** first appeared in OpenBSD 2.3.