As for "NeXT machine's software RIP", Rick Rashid, who was central in the development of that software, was my office neighbor. He left to take a position at Microsoft as VP of Research. I wonder if the software is RIPing.
--- Frank C. Wimberly 140 Calle Ojo Feliz, Santa Fe, NM 87505 505 670-9918 Santa Fe, NM On Fri, Oct 21, 2022, 3:08 PM Steve Smith <[email protected]> wrote: > FWIW, I dipped into the higher levels of real-time-systems development > several times in my career. The earliest being a control system (circa > 1981) for the LANL Proton Storage Ring where one naturally can't afford > anything *but* failsafe implementations, etc. The stakes are just too > 'ffing high and the coupling to electrooptomechanical systems quite > intimate. > > The "digital" components of such systems might have had the opportunity > to ignore timing issues and simply "execute the same steps" regardless > of timing. But in fact many software-driven (sub)systems represented > time-critical processes and sometimes were up agains the timing limits > of the analog components which had no leeway in their "execution". > > There are all kinds of analogies in federated (distributed) simulation > environments which Glen (and others here) probably know much better than > I, where different "clocks" matter, and different levels of > synchronization and reproducibility are in play. The Postscript > interpreters, printers, and film recorders were also pseudo real-time > systems since some of the timing components were in fact software > controlled (for example, the film recorders were "stroke" devices with > software driving D-A converters to "sweep" out vectors and "clip" the > on/off of the beam with appropriate analog component delays/biases/gains > needing to be calibrated for. Fortunately failures in this step did > not (usually) damage anyone or risk anyone's health and safety (like the > beam in the PSR did). > > Regarding identity and equivalence, I prefer the phrase: "close enough > for who it's for"... > > > On 10/21/22 11:18 AM, glen wrote: > > Ha! If we're going to argue about words, then let's stick with the > > word "identity" and skip the "metaphor" nonsense. You and Frank seem > > to be using the word in a weird way. Identity means "the exact same > > particular thing over any differencing available" or somesuch. I mean, > > it's used that way in phrases like "identity theft" as well as > > mathematical identity. It's equivalence sets all the way down. I just > > can't imagine any working computationalist would ever say anything > > like "executed identically" unless ... well ... the exact same > > process, with the exact same steps, happened. > > > > I suppose there are deep philosophical intuitions pried at by the > > words "emulation" versus "simulation". And one can argue (again with > > help from Christian List) about whether there exist fully closed > > ontological walls like we try to create with things like Jails, > > HyperV, Docker, VM's like Java's, etc. But "execute identically" is a > > phrase that would only be used by someone who worked *way* above such > > levels (assuming levels even exist at all). It's a bit like talking to > > the kids programming websites these days, with access to infinite disk > > space, infinite memory, steeped in continuous delivery, etc. [⛧] > > > > Layers of abstraction are fine. Use 'em when you need 'em. But we > > shouldn't posture by invoking things like "instruction sets" and > > "execute identically" in the same breath. (Not that you did that ... > > just sayin'.) > > > > > > [⛧] Rant: This is a good talk > > <https://www.youtube.com/watch?v=8Ab3ArE8W3s>. But I get super > > irritated when people use *toy* code in their rhetoric and leave large > > scale deployment as an exercise for the reader. Yeah, fine. The REPL > > is cool and all. But when my simulation takes a fvcking WEEK to > > execute, it's difficult to sympathize. I've recently been playing > > around with VSCodium, which is pretty cool. But whatever, man. I still > > have to upload the code somewhere and execute it. Get off my lawn! > > > > On 10/21/22 09:24, Steve Smith wrote: > >> > >> As a counter-example, we ran film recorders whose "guts" were built > >> by Ed Fredkin's Information International company and were built to > >> the spec of Dec PDP-11 (I think 11?) and it was anecdotally agreed > >> among the user community (of a few thousand delivered units in the > >> world?) that these PDP-clones *never* failed to execute the code > >> identically to the machines they were patterned after. I don't > >> remember the details of implementation of these 70's era hardware > >> designs, but I understood that they III designed their own PCBs but > >> (obviously?) used the same CPU chips... I don't know about all the > >> other support components... A likely answer to this pondering is that > >> these machines did not run a general purpose OS and the III > >> software/system people probably made up for any differences in > >> Software/Timing/Error Handling? > >> > >> If Owen is listening in here, I think he was there for more than a > >> little of this from inside Apple/Sun? > >> > >> - Steve > >> > >> PS. To concede/confront glen's sentiment that: " 'Metaphor' is an > >> evil word, used only by manipulators and gaslighters", I would > >> offer that the use of *conceptual metaphor* is to thinking as noise > >> is to simulated annealing, and his point about "tighter or looser > >> equivalence" might well be the best argument *for* the use of > >> metaphorical thinking? I can't believe I'm stirring/kicking this can > >> of worm-hornets down the street again... > >> > > > > -. --- - / ...- .- .-.. .. -.. / -- --- .-. ... . / -.-. --- -.. . > FRIAM Applied Complexity Group listserv > Fridays 9a-12p Friday St. Johns Cafe / Thursdays 9a-12p Zoom > https://bit.ly/virtualfriam > to (un)subscribe http://redfish.com/mailman/listinfo/friam_redfish.com > FRIAM-COMIC http://friam-comic.blogspot.com/ > archives: 5/2017 thru present > https://redfish.com/pipermail/friam_redfish.com/ > 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/ >
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