Pseudonymous engineer “rscott2049,” hereafter merely “Scott,” desires to place a Digital DECstation MIPS-based workstation in your pockets — because of a Raspberry Pi RP2040-powered emulator the dimensions of a enterprise card.
“It is a customized RP2040 primarily based enterprise card that runs Ultrix/DECwindows,” Scott explains of the gadget, dubbed the DECstation 2040. Impressed by the DECstation line-up of the late Eighties, launched by Digital with the declare of being the world’s quickest UNIX workstation, the DECstation 2040 swaps out the unique gadget’s MIPS processor for an Arm-based Raspberry Pi RP2040 — a microcontroller, however one delivering sufficient of a lift in efficiency to emulate its ancestor completely.
Constructing atop Dmitry Grinberg’s earlier LinuxCard undertaking, which emulated a MIPS-architecture system on a Microchip ATSAMD21 microcontroller, the DECstation 2040 runs its RP2040 chip closely overclocked to 300MHz and provides 8MB of SPI-connected flash reminiscence and 32MB of pseudo-static RAM (PSRAM) to work across the chip’s somewhat-limited 264kB of inner SRAM. That is pushed from the RP2040’s programmable enter/output (PIO) blocks, delivering 42 and 32MB/s of write and browse bandwidth respectively.
Regardless of its small measurement, becoming into the footprint of a enterprise card, the gadget additionally features a microSD Card socket for storage enlargement, a VGA video output delivering a surprisingly excessive 1024×864 decision, Ethernet connectivity, and a USB interface for a keyboard and mouse. This latter function contains conversion to the DECWindows commonplace — permitting fashionable peripherals to regulate the system, which is designed to run Digital’s Ultrix UNIX distribution and, optionally, the DECWindows desktop atmosphere on high.
The ultimate revision of the {hardware} contains full-size VGA, Ethernet, and USB connectors. (📷: rscott2049)
“This undertaking has been a voyage of discovery,” Scott concludes. “The primary doc/build_log.txt entry was on 23-Mar-2023, however I might been considering of constructing a enterprise card ever since I might learn Dmitry’s LinuxCard internet web page. I’ve discovered the right way to use the RP2040 PIO engines and the DMA subsystem to push pixels. I am amazed at how versatile and succesful the RP2040 has turned out to be. Hats off to the RP2040 designers!”
The undertaking is documented in full on Scott’s GitHub repository, with {hardware} design information and firmware sources launched below the permissive BSD 3-Clause license; extra info is out there on Hackaday.io.