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The DECchip 21064 and DECchip 21064A Alpha AXP PCI Evaluation Board (EB64+) is an evaluation and development board for systems based on the 21064 or 21064A microprocessor and the 21072 chipset, released in 1994. Aspen Systems sold a closely related board as the Alpine (see Clones and OEM Systems).

The EB64+ is a different board from the AlphaPC 64 (Cabriolet), which was derived from it. Because Linux handles both with the same code, the names are often used interchangeably on mailing lists.

• 21064 or 21064A CPU running at 150 MHz to 275 MHz ¹⁾
• 21072 chipset (1x 21071-CA cache/memory controller, 1x 21071-DA PCI bridge, 4x 21071-BA data slices)
• 512 KiB, 1 MiB, or 2 MiB Bcache
• 8x 72-pin 36-bit SIMMs (32 data bits, 1 parity bit, 3 unused bits) in two banks of four, supports 16 MiB to 512 MiB of 70 ns or faster FPM DRAM, 128-bit data bus
• PCI bus running at 25 MHz to 33 MHz
• 1x 32-bit PCI slot plus 1x shared PCI/ISA slot
• 2x ISA slots plus 1x shared ISA/PCI slot
• Intel 82378ZB or 82378IB PCI-to-ISA bridge
• NCR 53C810 SCSI, internal and external headers on motherboard
• DECchip 21040 Ethernet with 10BASE-T and 10BASE2 interfaces
• National 87312 combination controller: floppy, 2x serial ports, parallel port
• Intel 8242 keyboard and mouse controller
• 512 KiB UVPROM containing the debug monitor
• Standard full-size PC AT board, 33.02 cm x 30.48 cm (13.0 in x 12.0 in) ²⁾
• Standard PC power supply (not included)

The EB64+ has two ROMs, one of which contains the Windows NT ARC firmware and the other contains the Evaluation Board Debug Monitor.

SIMMs are installed in two banks of four. Jumpers select the Bcache size and whether the Bcache uses 10 ns or 15 ns SRAM timing; main memory needs no jumpers.

True parity SIMMs are required; "logic parity" SIMMs, which generate the parity bit with logic instead of storing it, do not work. ³⁾

The firmware is stored in UV EPROMs rather than flash, so it cannot be updated in place. DEC's ARC firmware release notes state that updating the firmware on an EB64+ requires obtaining an updated ROM from the system vendor, whereas the AlphaPC 64 can be updated with fwupdate.exe. ⁴⁾ The last ARC release for the EB64+ and AlphaPC 64 was 4.49-7. ⁵⁾

An SRM console also exists for the EB64+. DEC distributed SRM consoles for its evaluation boards (EB64, EB64+, EB66, EB66+, Cabriolet, EB164, PC164, LX164, SX164) as part of its evaluation board software development kit. ^{6) 7)}

Linux 6.9 was the last version to support the EB64+; Linux 6.10 removed support for processors older than the EV56 (21164A). ⁸⁾ Kernels up to 6.9 support it with CONFIG_ALPHA_EB64P_CH (the "EB64+" system type) or a generic kernel. ⁹⁾ The kernel uses the same machine vector for the EB64+ and the Cabriolet, and distinguishes the two at boot. ¹⁰⁾

Linux can be booted either from the ARC console using MILO (image name eb64p) ^{11) 12)}, or from an SRM console, if one is installed, with aboot. ¹³⁾

In kernels up to 6.9, the onboard devices use these drivers:

• SCSI (NCR 53C810): sym53c8xx. ¹⁴⁾
• Ethernet (DECchip 21040): de2104x; the tulip driver does not list the 21040's PCI ID. ^{15) 16)}
• Serial ports (PC87312): 8250, at the standard PC addresses listed in the Alpha serial port table. ¹⁷⁾
• Parallel port: parport_pc; floppy: floppy; keyboard and mouse: i8042. ^{18) 19) 20)}

• Clock battery: the Dallas DS1287A time-of-year clock contains a sealed lithium cell that keeps the clock and its RAM running without power, ²¹⁾ so the chip itself must be replaced once the cell is exhausted. For a replacement part, see AXPpci 33: Known issues. See also Systems: Common problems.

Aspen Systems sold the Alpine, a close clone of the EB64+ with 3 PCI and 3 ISA slots. ^{22) 23)} Unlike the EB64+, the Alpine has a single ROM, which contains the Windows NT ARC firmware. ²⁴⁾ The ROM is a socketed EPROM rather than flash, and Aspen supplied replacement firmware PROMs, including one containing SRM. ^{25) 26)} Like the EB64+, it has onboard NCR 53C810 SCSI.

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

• Aspen Telluride
  • "DEC systems equivalents to Aspen Systems", Brian Cruikshank, axp-list, 21 Jun 1996: "Telluride PC64"
  • "setting the record straight", Randy Perry, axp-list, 12 May 1996: "Telluride 21064 7 PCI and 3 ISA"
  • "Re: linux on EB164+", Jim Paradis, axp-list, 12 May 1996: "Aspen Telluride. This is an EB64+ with the PCI-PCI bridge."