i think contiki needs less than 16k of ram to run a webserver, most of which is the tcp stack. my own httpdito is about 2k of code and uses a 1024-byte data buffer, but that's sweeping tcp under the linux kernel rug
this is just to say that you could probably have run a webserver on a pdp-8/s, which was about the size of an atx case and would be a reasonable controller to build into a phototypesetter at the time