daveb@geac.UUCP (David Collier-Brown) (01/08/88)
In article <1497@osiris.UUCP> mjr@osiris.UUCP (Marcus J. Ranum) writes: > There would be a few problems with making UNIX ROM-only - at least >the root file system: there are all the various files in /etc that do >benefit from the occasional change. >... I can cite the PC as an example... As soon as you >start offloading parts of your software onto the hardware, you trade speed >for flexibility. Well, Apple is doing it right now, with substantial parts of their runtime support in rom, accessable via vectors in ram. The operating system happily inserts corrections, amendments and upgrades by plugging addresses on startup. In fact, the mechanisms for dealing with continuous change were known by the ARPAnauts and Multicians before Unix ever saw the light of day: tag code and data with version numbers, provide translation software whenever the versions change incompatably, and make code and data structures replacable at run-time without disturbing running processes. Its tricky, but is sure isn't **hard**. And it's been re-invented and is being used right now. --dave -- David Collier-Brown. {mnetor|yetti|utgpu}!geac!daveb Geac Computers International Inc., | Computer Science loses its 350 Steelcase Road,Markham, Ontario, | memory (if not its mind) CANADA, L3R 1B3 (416) 475-0525 x3279 | every 6 months.