I've written another essay about my mad #PostScarcitySoftware #Lisp system.

"We don't need to know, or have known, these people to build on their work. We don't have to, and cannot in detail, fully understand their work. There is simply too much of it, its complexity would overwhelm us.

We don't know. We don't care. And that is a protective mechanism, a mechanism which is necessary in order to allow us to focus on our own task, if we are to produce excellent work."

https://www.journeyman.cc/blog/posts-output/2026-03-20-Dont-know-dont-care/

Don't know, don't care

Modern computing systems are extremely complex. It is impossible for someone to be expert on every component of the system. To produce excellent work, it is necessary to specialise, to avoid being distracted by the necessary intricacies of the things on which your work depends, or of the (not yet conceived) intricacies of the work of other people which will ultimately depend on yours. It is necessary to trust

The Fool on the Hill

In researching that essay I've reminded myself of two very old papers on building #Lisp specific processors.

There's one on the Symbolics Ivory processor here -- this was a real commercial product, not just a research experiment:

https://gwern.net/doc/cs/hardware/1987-baker.pdf

There's a paper by Guy Steele and Gerald Sussman on an experimental processor (again, real silicon) here:

https://web.archive.org/web/20060210225611/https://repository.readscheme.org/ftp/papers/ai-lab-pubs/AIM-514.pdf

The Xerox D-machines (Dorado, Dandelion, Daybreak, and a couple of others whose names I forget) used processors which weren't strictly Lisp-specific silicon, but they did run #Lisp specific microcode, which is interesting in itself.

Reference manual here:

https://web.archive.org/web/20181106002400/https://doc.lagout.org/science/0_Computer%20Science/0_Computer%20History/old-hardware/xerox/6085/daybreak/Daybreak_Technical_Reference_Manual_Dec86/TechRef_0.pdf

Thanks to @internetarchive for preserving these links!

Wayback Machine

@simon_brooke @internetarchive

"Dolphin" was the other one.

@weekend_editor @internetarchive Also Dandytiger, which if I recall correctly was an upgraded Dandelion and may not have been an official name(?)
@simon_brooke alice graph reduction machine was all about parallel evaluation of lambda-expressions
https://dl.acm.org/doi/10.1145/800223.806764