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The Digital AXPpci 33 is a baby AT motherboard built around the DECchip 21066 family, whose code name is Noname. ¹⁾ It was designed by Digital's Technical OEM group and shipped with no CPU, cache, or memory installed, leaving the system integrator to fit the level of performance wanted. ²⁾ The board first shipped in October 1994, and the design guide was revised for 233 MHz operation in August 1995. ³⁾ It descends from the EB66, being based on revision 1 of the EB66 design. ⁴⁾

The Multia (UDB) uses the same processors and the same interrupt handling, and Linux treats the two as one platform, so "Noname" in Linux documentation, kernel images, and MILO images usually covers both. They are different products: the AXPpci 33 is a bare OEM motherboard, while the Multia is a complete small desktop with onboard TGA graphics and Ethernet, essentially a miniaturized Noname. ⁵⁾

• DECchip 21068 at 66 MHz, 21068A at 100 MHz, 21066 at 166 MHz, or 21066A at 233 MHz, in a ZIF socket; the frequency is set by jumper J7, which also has settings for 133, 200, 266, and 300 MHz marked reserved ^{6) 7)}
• PCI bus and memory controller integrated into the CPU, so there is no separate chipset; PCI runs at 33.33 MHz
• 0, 256 KiB, or 1 MiB of external cache in 11 DIP sockets, 15 ns or 20 ns, selected by jumper J17
• 4x 72-pin 36-bit SIMM sockets in two banks, 70 ns, 8 MiB to 256 MiB, ECC protected, 64 data bits plus 8 ECC bits
• 512 KiB flash ROM, 8 KiB battery-backed NVRAM, and a serial ROM
• 3x 5 V 32-bit 33 MHz PCI slots and 5x ISA slots, seven bulkhead positions in total because one long PCI slot shares a bulkhead with one long ISA slot
• Intel 82378ZB SIO PCI-to-ISA bridge ⁸⁾
• NCR 53C810 fast SCSI-2 controller on the PCI bus, single-ended, 10 MB/s synchronous, seven devices
• National PC87312 Super I/O controller providing IDE, diskette, 2x serial ports, and a parallel port
• Intel 8242 keyboard and mouse controller; AT or PS/2 style connectors depending on the board variant ⁹⁾
• Dallas Semiconductor DS1287A time-of-year clock, which also drives the CPU's periodic interrupt on IRQ[2] ¹⁰⁾
• Two RS-423 compatible 9-pin serial ports and one Centronics parallel port
• 220 mm x 353 mm, baby AT, standard AT power supply voltages; +3.3 V is supplied for PCI options only

SIMMs must be installed in like pairs, and either bank may hold the first pair. Any mix of pair sizes is allowed as long as both SIMMs of a pair match. Supported sizes are 4, 8, 16, 32, and 64 MiB, and 64 MiB SIMMs require serial ROM version 0.4 or later. ¹¹⁾ SIMMs with two RAS lines are addressed as two separate memories, with the split bank enable bit set in the bank configuration register; the larger SIMMs must be placed at the lower addresses, because each bank's base address has to be naturally aligned with its size. ¹²⁾

The board needs 36-bit SIMMs. Like the Jensen, and unlike later boards, it has a 64-bit memory bus and so takes SIMMs in pairs rather than sets of four. ¹³⁾

Cache is optional and the board runs without it. ¹⁴⁾ If fitted, all 11 sockets must be filled with identical devices from one vendor: 11x 32Kx8 SRAMs in 28-pin DIPs for 256 KiB, or 11x 128Kx8 SRAMs in 32-pin DIPs for 1 MiB. The eleventh device holds the ECC bits, so 352 KiB of SRAM yields 256 KiB usable and 1.408 MiB yields 1 MiB. The CPU determines the cache size at power-on; only the access time is set by hand, with jumper J17 out for 15 ns parts and in for 20 ns parts. ¹⁵⁾ Some 128Kx8 SRAMs are packaged only for the narrow 28-pin footprint and do not fit. ¹⁶⁾

The flash ROM holds one console at a time, either ARC for Windows NT or SRM for Digital UNIX, and either can be overwritten with the other. Updates are done from a floppy: a FAT floppy with fwupdate.exe through the ARC "Install new firmware" menu item, or an SRM boot block floppy written from the firmware image, booted with b dva0 and updated with update srm or update arc. The last version distributed by Digital is V1.4, which contains ARC 4.42 and SRM X4.3-3114 and needs at least 16 MiB of memory to run. ^{17) 18)} A later update, V1.6, carries SRM X4.7-1760, ¹⁹⁾ and the V7.3 firmware CD lists 4.7 as the last SRM version for the board (see SRM Console: Final versions).

The serial ROM is a separate socketed part. Version 0.5, distributed as an Intel hex file for a ROM programmer, is required for 233 MHz operation, and version 0.4 or later is required for 64 MiB SIMMs. ^{20) 21)}

Unlike the AlphaPC 64, the board has a fail-safe loader. Moving the SROM select jumper from J28 to J29 pins 1-3 makes the serial ROM load the console from floppy instead of from flash, which recovers a board whose flash was corrupted by an interrupted update. The same jumpers select a service console with the Bcache enabled or disabled. ²²⁾ A board with MILO flashed over the console can be restored to SRM this way, using the UDB fail-safe floppy image udbfs138.img and a terminal on the first serial port. ²³⁾

Linux 6.9 was the last version to support the AXPpci 33; Linux 6.10 removed support for processors older than the EV56 (21164A). ²⁴⁾ Kernels up to 6.9 support it with CONFIG_ALPHA_NONAME_CH (the "Noname" system type, shared with the Multia) or a generic kernel. ²⁵⁾ Kernel images and MILO images for the board are named noname. ^{26) 27)} In 2019, Debian's generic uniprocessor kernel, 4.19.0-5, booted on an AXPpci 33. ²⁸⁾

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

• SCSI (NCR 53C810): sym53c8xx. ²⁹⁾
• IDE (PC87312): the interface is not a PCI device, so it is handled by pata_legacy, which probes the legacy ports at 0x1F0 and 0x170 when no PCI controller claims them. ³⁰⁾ No Linux driver was written to use more than PIO modes on the PC87312. ³¹⁾
• Serial ports: 8250, at the standard PC addresses listed in the Alpha serial port table. ³²⁾
• Parallel port: parport_pc; floppy: floppy; keyboard and mouse: i8042. ^{33) 34) 35)}

Boards with the SRM console boot Linux with aboot. From ARC, MILO is loaded with linload.exe and a noname.arc image on a FAT floppy or partition, or it can be written to flash with fmu, run from MILO itself, which builds the flash header these boards need. ^{36) 37)}

• PCI interrupt routing: in kernels up to 6.9, the routing table for the Noname assigns IRQ 13 to one of the PCI slots, and IRQ 13 is never delivered, so a card in that slot receives no interrupts. Moving the card to another slot avoids the problem, as does changing route_tab in arch/alpha/kernel/sys_sio.c from 0x0b0a0f0d to 0x0b0a0f0f. ^{38) 39)}
• 64 MiB SIMMs: a board whose serial ROM predates version 0.4 sizes 64 MiB SIMMs incorrectly; a pair of 16Mx36 SIMMs has been seen to come up as 32 MiB rather than 128 MiB. ^{40) 41)}
• Clock and NVRAM batteries: the time-of-year clock is a Dallas DS1287 and the NVRAM a Dallas DS1225AD-150, and both have their own batteries. When these batteries are exhausted, the board forgets its SRM settings at every power cycle, the console shows a wrong date, and Tru64 UNIX warns that the TOY battery is low. ⁴²⁾ The DS1287's lithium cell is sealed inside the chip, so the whole chip is replaced; see EB164: Known issues. Replacing the DS1287 with a DS12887+ and fitting a new DS1225 restored both the settings and the clock. ⁴³⁾ A board with a depleted NVRAM battery still boots Linux. ⁴⁴⁾ See also Systems: Common problems.
• Serial ports: the two ports are RS-423 rather than RS-232, on 9-pin connectors, and modems and mice that work elsewhere have been reported not to work on them. ⁴⁵⁾
• Graphics card initialization: the console firmware lacks the VGA BIOS emulation needed by many later cards. MILO includes Digital's BIOS emulation and initializes far more cards. ^{46) 47)}

Bare boards carry no processor, cache, or memory; preconfigured boards add a processor but still no cache or memory. ⁴⁸⁾

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

• Slot count
  • Digital AXPpci 33 Alpha PC Motherboard OEM Design Guide: "Total of seven option slots", three PCI and five ISA, one long PCI slot sharing a bulkhead with one long ISA slot.
  • des_pci33.html, Digital, ftp.digital.com/pub/Digital/axppci/: "4 ISA slots, 2 PCI slots, 1 ISA/PCI shared slot".
  • "Re: Good deal on NoName?", Stephen J. Gaudet, axp-list, 7 Jun 1996: "the AXPpci33 has 3 PCI and 4 ISA".
  • "AXPpci33 mboards", Dave Gavin, axp-list, 21 Mar 1997, quoting a reseller: "5 ISA and 3 PCI (one shared)".