Alphabox brings DEC Alpha machines back from the dead.

It doesn't merely execute Alpha instructions. It recreates the machines around them: the chipsets, the firmware, the buses and interrupt wiring, the SCSI adapters, network cards and graphics chips. It does so closely enough that software written for them a quarter of a century ago runs without noticing the hardware is gone.

Boot DEC's own SRM console. Start AlphaBIOS from it. Install Windows 2000 and let Microsoft's own ATI driver find an emulated 3D Rage Pro and draw Direct3D scenes on it. Boot OpenVMS on sixteen EV7 processors in a machine that once filled a cabinet. And on a modern laptop, the Alpha you are pretending to own runs faster than the real one ever did.

Alphabox keeps the Alpha as it was, and also shows what it could have become. It gives the platform things it never had, such as USB 2.0 and virtio drivers for Alpha Windows and Direct3D with hardware transform and lighting on a Radeon, and holds each one to the same test as the real hardware: it has to work under a real Alpha operating system.

OpenVMS 8.4 with the CDE desktop	Windows 2000 on two Alpha processors	Direct3D on an emulated ATI 3D Rage Pro

What is this?

Not a generic Alpha emulator. Alphabox emulates specific, real machines (the AlphaServer ES40 first, and now eleven of them, from the DS10 to the GS1280) well enough that their original firmware, operating systems and device drivers take them for the real thing:

• OpenVMS 8.4, Tru64 UNIX, Linux, NetBSD, Windows 2000, and the 64-bit Windows Microsoft built on the Alpha and never shipped
• the EV68 (21264) on the Tsunami and Titan chipsets, and the EV7 (21364) with its on-chip router, up to sixteen of them; and the beginnings of the EV8 (21464), the Alpha Compaq cancelled before it was built
• the cards' own VGA BIOSes, and Windows' own drivers for Symbios, QLogic, S3, Cirrus, ATI, 3Dlabs and DEC hardware
• Direct3D on graphics chips from 1998, USB 2.0, SMP
• about 3000 MIPS per emulated CPU on an Apple M3 Max, two to three times the ES40's own 667 MHz EV68 (how it is measured)

The Alpha outlived its maker; the machines mostly didn't. They are rare now, their disks are dying, and their software, a whole branch of computing history, is running out of places to run. Alphabox is one of those places.

How real is it?

Alphabox emulates the hardware and lets the original software find it. Windows 2000 loads its Symbios driver because it finds a Symbios 53C875 in PCI configuration space. AlphaBIOS runs the graphics card's own x86 VGA BIOS. OpenVMS discovers an ES47 through the same console callbacks and management processor it would on HP's hardware.

So the test of correctness is simple: if the original driver doesn't work, Alphabox is wrong. That is the difference from QEMU, which runs Alpha code well, for Linux, with its own PALcode and firmware in place of DEC's: Alphabox runs the genuine consoles, and so the operating systems that depend on them.

Things that shouldn't work, but do

OpenVMS 8.4 on an emulated ES47: two EV7s, the CDE login on its Radeon 7500	dxdiag: ATI's own Direct3D driver, every test passed	Windows 2000 reading a USB disk

The 64-bit Windows that never shipped: Whistler build 2210 for AXP64	A 64-bit command prompt on a 21264	The same Windows on two Alpha processors

• Direct3D on Windows for Alpha. The ATI 3D Rage Pro, 3Dlabs Permedia 2 and S3 ViRGE are emulated well enough that the Direct3D drivers on the Windows 2000 CD draw lit, textured scenes, checked pixel by pixel against Direct3D's software rasteriser.
• USB 2.0 on an operating system that never had it. The driver was written with nada, a companion C compiler that targets Alpha Windows; so were virtio drivers and a Radeon 7500 driver with a Direct3D 7 HAL (guest drivers).
• The 64-bit Windows Microsoft never shipped. Windows "Whistler" build 2210 for AXP64 installs through AlphaBIOS and runs native 64-bit programs, on one processor or two.
• Sixteen EV7s booting OpenVMS. The ES47 (two EV7s), ES80 (eight) and GS1280 (sixteen) boot OpenVMS 8.4 from an installed disk, through a management-processor protocol HP never documented.
• The Alpha that was never built. Compaq cancelled the EV8 in June 2001, late in its design. Following its internal design specification, Alphabox runs it in the EV7's place on the ES47, ES80 and GS1280: the EV7's console starts it, and OpenVMS 8.4 and Linux boot on it on the ES47. So far it is the EV7-compatible mode and the EV8's first new instructions, among them the ones it was to synchronise its threads with: a processor can sleep on a lock until another one writes it, and a Linux program on two emulated EV8s does. Its four threads per core can be shown to the console as processors of their own (tpus = 4, an Alphabox construction, not the chip's own behaviour), and OpenVMS and Linux then run on all eight threads of an ES47. The Tarantula vector unit is planned (the EV8).

What runs

Linux 7.0 on the ES40	The NetBSD 10.2 installer	A Japanese Windows 2000 beta, build 1877

Every guest below with media in the lab is booted and checked by test/tools/guests_check.sh (development.md).

Guest	Status
OpenVMS 8.4	Installs from its CD and boots to login on every emulated machine, with up to sixteen CPUs; DECwindows on the Permedia 2 and the Radeon 7500 (notes, installation guide)
Windows NT / 2000	Installs and runs through AlphaBIOS, on up to two CPUs, with each graphics card's own driver from the installation media (installation guide)
Windows "Whistler" 64-bit (AXP64, build 2210)	Installs and runs through AlphaBIOS, on up to two CPUs
Linux	Gentoo's install CD boots to a shell, and a system installed from it boots from disk to a login, where gcc works: on the ES40 with one or two CPUs, on a serial or VGA console, and on the ES47, ES80 and GS1280 with two or four EV7s (notes)
Tru64 UNIX	Boots
NetBSD	Boots; the 10.2 install CD boots to its installer (installation guide)

Emulated hardware

Area	Devices
Machines	AlphaServer ES40, DS20E, DS20, DS20L, DS10 (Tsunami); ES45, DS25, DS15 (Titan); ES47, ES80, GS1280 (EV7, "Marvel")
CPU	EV68CB (21264), 1–4; EV7 and EV7z (21364), 2–16; the cancelled EV8 (21464), in an EV7-compatible mode, 2–16, with its threads as processors up to 32; on the ES40 the EV7, EV7z or EV8 too, 1–4, a machine that was never built
Storage	Symbios 53C8xx and QLogic ISP SCSI; ALi and CMD 649 IDE; floppy; virtio-blk
Graphics	S3 Trio64; Cirrus GD5430/5434; ATI Mach64 through the 3D Rage Pro; 3Dlabs Permedia 2; S3 ViRGE family; DEC TGA and TGA2; ATI Radeon 7500
Network	DEC Tulip 2104x/2114x; Intel 8255x (DE600, DE602); virtio-net
USB	OHCI and EHCI controllers; tablet, keyboard, disks, speaker, host passthrough
Other	Ensoniq ES1370/ES1371 sound; DEC PCI-PCI bridges; serial ports, keyboard, mouse

The full list, chip by chip, is in docs/hardware.md; what is not emulated, and where a model is known to differ from the real part, in docs/limitations.md.

Quick start

git clone --recurse-submodules https://github.com/artur/alphabox
cd alphabox
cmake -S . -B build
cmake --build build -j
./build/alphabox configure    # writes es40.cfg
./build/alphabox run

You also need an SRM console ROM image, and a VGA BIOS for the graphics card. Optional build dependencies (libpcap, libusb, and libslirp for the built-in NAT network, which needs no privileges) are listed in building. libslirp and libpcap are also optional at run time: the binary starts without them, and a NIC that uses type = "nat" or the pcap back end loads its library then (on Linux apt install libslirp0 or libpcap0.8; on macOS brew install libslirp, and macOS ships libpcap). The documentation covers the rest: building, running and configuring, the machines, USB, headless operation and development and testing.

History and license

Alphabox began as es40, by Camiel Vanderhoeven and the ES40 Emulator Project, revived as AXPbox by Tomáš Glozar and Remy van Elst. Much of its CPU core, the x86-64 JIT and several devices were written by gdwnldsKSC and the contributors of ES40-Emu, and ported in 2026. This repository continued AXPbox as its own project, adding the AArch64 JIT, the machines beyond the ES40, USB and most of the device families, and was renamed Alphabox in 2026. It builds on MAME, Bochs, QEMU, 86Box, Mesa and others: docs/acknowledgements.md.

GNU General Public License, version 2 or later: see LICENSE. Third-party code keeps its original license, as noted in the source file headers and listed in docs/acknowledgements.md; this repository's changes to code that came under a permissive license are distributed under that license too.