#+TITLE: CLOSOS: Persistence by Default (Single Memory Abstraction)
#+ID: closos-memory-persistence
#+DATE: 2026-03-22
#+FILETAGS: :architecture:lisp:os:closos:persistence:

* Concept
CLOSOS eliminates the distinction between volatile primary memory (RAM) and permanent secondary memory (Disk). Primary memory functions as a transparent cache for a persistent object store.

* Key Principles
- *The Living Image:* The system state is permanent. "Saving" is not an explicit user action; changes are inherently persistent in the object store.
- *Undo Facility:* Since data is permanent, application writers are encouraged to implement sophisticated undo/redo facilities rather than manual file saves.
- *Atomic Snapshots:* High-integrity state is maintained via atomic flips and log-structured techniques, ensuring the system can recover from crashes without data loss.

* Source
:PROPERTIES:
:ID:       9c69a9ab-1c96-490e-9a8e-fbeafacba30e
:END:
- [[attachment:strandh-lispos.pdf][Robert Strandh, "CLOSOS: Specification of a Lisp operating system" (2013)]]