The SDF Parties Like It's 1993 by Putting a DEC PDP-10 Compatible Online for Public Access

The Super Dimension Fortress (SDF), a group of computer enthusiasts and professionals with an eye on classic UNIX systems, has put a new system online for public use — though given that the hardware, a Systems Concepts SC-40, dates back to the early 90s the word "new" may be misapplied.

Founded by Stewart Nelson and Mike Levitt, Systems Concepts made a name for itself creating accessories for the Digital PDP-10 family of mainframe computers before branching out into building its own PDP-10 compatible clone systems. While its systems were faster and more energy-efficient than Digital's own, missed deadlines plagued the project — and the release in 1993 of the SC-40, designed to be up to eight times faster than DEC's KL-10, would be the last in the range.

The SC mainframe family might be gone, but it's not forgotten. The SDF group has got its hands on an original unit, lovingly restored and now available for public use — accessible to anyone with an SSH client and an internet connection, in an announcement brought to our attention by Adafruit.

Part of the group's mission to provide remotely-accessible computing systems as a "non-commercial INTERNET," capitalization the SDF's original, the "new" SC-40 joins a range of DEC Alpha and AMD Opteron systems running NetBSD, TOPS-20, and Symbolics GENERA already installed and maintained by the group — and on which anyone is invited to log in and experiment with vintage computing.

The group has a long history of working with PDP-10 and compatible systems, stretching back to efforts in 1994 to bring a DECSYSTEM-2065 recently retired by the Texas Woman's University back online. With original hardware often hard to find and even harder to house, the focus was primarily on software emulation using more modern hardware to bring TOPS-10 and the newer TOPS-20 to a fresh audience — but now the SC-40 provides a fully-functional period-appropriate hardware platform, living alongside the SDF's existing XKL Toad-2, a single-chip reimplementation of the DECSYSTEM-20.

Those interested in trying out the SC-40 can simply SSH to sc40@hie.sdf.org and type "login new new" to enter the system and receive basic instructions on its use; a range of software has been pre-installed, with more — including games — to follow. More information about the SDF, meanwhile, is available on the organization's website.