"How do you fit a dictionary in 64kb RAM? Unix engineers solved it with clever data structures and compression tricks. Here's the fascinating story behind it."
Mentioned by Aharon Robbins on the TUHS mailing list https://www.tuhs.org/pipermail/tuhs/2025-January/031371.html
Links to documents describing transputers and the Helios operating system, which has a GPL v3 licensed NG variant, https://github.com/axelmuhr/Helios-NG which appears to be dormant.
Mentioned on the TUHS mailing list https://www.tuhs.org/pipermail/tuhs/2024-September/030872.html
Some interesting documents are
There Is No Royal Road to Programs - A Trilogy on Raster Ellipses and Programming Methodology (M. Douglas McIlroy)
MM 67-4734-7 1967-05-15 2.54 MB An Introduction to the Available Programs and Other Design Aids for the Design of Filters, Equalizers and Other Networks
MM 67-5311-18 1967-08-29 1.27 MB Notes on the Design of Cosine Roll-Off Filters
Sail is a language for defining the instruction-set architecture (ISA) semantics of processors: the architectural specification of the behaviour of machine instructions. Sail is an engineer-friendly language, much like earlier vendor pseudocode, but more precisely defined and with tooling to support a wide range of use-cases.
Found on the CHERI page https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/
A DECstation emulator on a business-card sized PCB. The description is a nice read. https://hackaday.io/project/196769-decstation2040 for a RP2040 version, with 32 MB HyperRAM, 1024 x 864 mono video, and USB mouse/kb