Alpha/Linux Wiki

The AlphaStation 600 (Alcor), AlphaStation 500 (Maverick and Bret), and Alpha XL 300, 366, and 433 (XLT) share the CIA core logic, EISA, and one kernel platform. ^{1) 2)}

• The AlphaStation 500 has a built-in QLogic ISP1020 SCSI controller and no IDE; its onboard sound is attached to an EISA bus ^{10) 11) 12)}
• The XLT and the AlphaStation 500 (Bret and Maverick) have a built-in 21040 Tulip Ethernet controller in PCI slot 6; the AlphaStation 600 has its 21040 on the separate I/O subsystem module instead (see below), not in slot 6 ¹³⁾

• CIA bridge and cache on the system board, with either 2 MiB or 8 MiB of cache depending on the model
• Memory as two banks of four 8-byte DIMMs, up to 1 GiB; a bank must be filled completely with identical DIMMs, and Digital recommended one vendor per bank
• 33 MHz PCI, 32-bit and 64-bit, on a riser card, plus an EISA-attached audio card and a media adapter unit header on the system board
• Models were upgraded by swapping the whole system board, keeping the memory, options, and drives ¹⁴⁾

• Direct-mapped, write-back, ECC protected board-level cache split across three SIMMs, all of which must be present; designs ran from 2 MiB to 16 MiB, with 4 MiB "typical"
• Two memory motherboards, which must both be present and symmetrically populated, each holding up to 16 standard 36-bit SIMMs, for 32 MiB to 1 GiB
• Eight option slots: three 64-bit PCI, one 32-bit PCI, one shared PCI/EISA, and three (E)ISA, of which the graphics, the I/O subsystem module, and the audio card take three, leaving five
• 33 MHz PCI only, and although the system generates and accepts 64-bit data it "does not generate 64-bit PCI addresses"
• Intel 82374EB and 82375EB PCI-EISA bridge, Intel 8242 keyboard and mouse controller, Dallas 1287 time-of-year clock, Dallas 1225 8 KiB battery-backed SRAM, and an 87312 combo chip for the serial and parallel ports and the floppy
• The I/O subsystem module is a separate PCI card carrying two QLogic ISP1020 SCSI chips, a DECchip 21040 Tulip Ethernet controller, and a DECchip 21050 PCI-to-PCI bridge ¹⁵⁾
• Early systems instead shipped with a KZPAA-AX single-ended narrow SCSI controller and either a DE435 Etherworks Turbo PCI card or a P2SE module ¹⁶⁾
• Memory is added in eight-SIMM increments, four per tower, in matching locations in each tower quadrant ¹⁷⁾
• The 333 MHz upgrade is not a CPU swap: the kit replaces the system board and the cache modules together ¹⁸⁾

• The AlphaStation 600 should be booted from the SRM console, loading the kernel with aboot or BOOTP, rather than from the ARC console with MILO. ¹⁹⁾
• The XLT has no official SRM console, because it was designed and sold for Windows NT only. ²⁰⁾ It can boot Linux only with MILO. ²¹⁾
• The AlphaStation 500 (Bret) is architecturally very close to the XLT, so the XLT build of MILO also works on it. ²²⁾

Current kernels support the AlphaStation 500/400 and 500/500, with CONFIG_ALPHA_ALCOR or a generic kernel, booted from the SRM console with aboot. Linux 6.9 was the last version to support the EV5 models; Linux 6.10 removed support for processors older than the EV56 (21164A). ²³⁾ The Alpha XL 366 and 433 have EV56 processors but no SRM console, and MILO did not load kernels from Linux 2.6.23 onward until a 2026 fix; no one has reported booting a current kernel on them (see MILO). ²⁴⁾

• An AlphaStation 500/266 or 500/333 can be brought up to a supported model by replacing its system board: Digital sold board swaps from the 500/266, 500/333, and 500/400 to the 500/500 (PB56U-BA, -BB, and -BC), which keep the memory, options, and drives. ^{25) 26) 27)}
• Use the final SRM version, V7.2-2 (see Final versions). For a serial console on COM1, see Using the SRM Console: Serial console.
• The QLogic ISP1020 SCSI controllers, on the AlphaStation 500 system board and on the AlphaStation 600 I/O subsystem module, use the qla1280 driver, which loads its firmware from linux-firmware. ²⁸⁾
• The built-in 21040 Tulip Ethernet uses the de2104x driver; the tulip driver does not claim the 21040. ^{29) 30)}
• The AlphaStation 500's onboard audio is a Microsoft Sound System card on the EISA bus, which may have to be configured with the EISA Configuration Utility before an operating system sees it. ³¹⁾
• The kernel recognizes the XLT and AlphaStation 500 boards at boot by the built-in Tulip in PCI slot 6, sets up their interrupts accordingly, and reports "Detected AS500 or XLT motherboard". ³²⁾

• Battery: on the AlphaStation 500, the time-of-year clock battery (see Common problems) is on the system board under the fan, which sits beneath the floppy and disk mounting unit. ³³⁾
• Revision 1 of the CIA core logic, used in the AlphaStation 500/333, the XLT, and the EB164, is flawed in how it handles some of its PCI DMA windows. ³⁴⁾ The kernel avoids the affected DMA windows on CIA revision 1, and as a result does not use 64-bit (DAC) PCI addressing there. ³⁵⁾

The AlphaStation 600 family, announced in July 1995, comprised "the first Digital workstations to use the Alpha 21164 chip", with "the first-in-the-industry 64-bit workstation PCI I/O bus". ³⁶⁾ A Digital Technical Journal paper describes its design. ³⁷⁾ The AlphaStation 600 5/333 followed on 29 January 1996, which Digital called "the world's first workstation to break the 400 SPECint92 barrier". ³⁸⁾

The AlphaStation 500 series was announced on 8 March 1996 alongside the AlphaStation 255, in 500/266, 500/333 and 500/400 models. ³⁹⁾

The following sources conflict with each other or with the account given above. They are listed here for further investigation.

• AlphaStation 500 memory modules
  • AlphaStation 500 Series User Information, p. 3-8: "The AlphaStation 500 Series memory sub-system has two banks of memory, which include (4 x 72) 8 byte Dual In-Line Memory Modules (DIMMs)."
  • "Re: Alphas worth saving?", Jay Estabrook, debian-alpha, 5 Feb 2003: "the Maverick takes EDO SIMM memory, which is hard to find"

• Alpha XL 366 CPU
  • "RE: RH 7.1 on XL366 ?", John Jemiolo, axp-list, 4 Sep 2001: "the XL366 contains a EV5 cpu"
  • "XL-266 install", Jeff Donsbach, axp-list, 20 Feb 2004: "the 300 was an EV5 while the 366 and 433 were EV56"