Restored PDP-11/83 Serves a Live Web Page on 2.11BSD Unix

The machine is built around a Mentec M11 CPU, with two chassis joined by M9404/M9405 cards. The configuration also lists an RQDX3 controller, two Emulex UC07 boards, a KDA50, an RLV12, a DEQNA Ethernet interface and an M3104 serial multiplexer. Storage consists of an RA82 drive plus dual RA92 drives, MFM disks for boot and swap, dual RL02 removable-pack drives, RX50 floppy drives and a TKZ50 tape drive.

A live panel is displayed at the top of the page, and the address /cgi-bin/webtop returns a raw snapshot. The post notes that a 16-bit httpd will not survive the front page, so Varnish, Caddy and Cloudflare are used to cache the HTML and a five-second webtop sample. The origin remains the PDP-11 itself, which handles all of the webtop and visitor-count requests.

Telnet access is available at pdp1173.com under the guest account, but the post warns that it is a 40-year-old UNIX with no modern security story. Visitors are asked not to treat it as a challenge box; the operator says a restore from tape is possible but would ruin the setup for everyone else.

Getting BSD running on the Mentec required a customized BSD kernel built to use FPSIM, because the Mentec supports IEEE floating-point formats and not the DEC formats.

The author of the post offered to answer questions about Mentec hardware, MSCP, Q-bus or 2.11BSD. At the time of posting, the item had drawn 22 points and four comments on Hacker News.