jim...@earthlink.net said: > Ah, but will the exact same single board computer be available for > replacement in 5 years? Or will it be Rev F instead of Rev B, with "just a > few tweaks to improve performance", but also enough that it's not "drop the > image on it and run"
> What about 10 years? 15? My straw man is to buy a bunch now and put them on the shelf until you need them? It would be interesting to read a good B-school type report on that topic. Is it realistic to expect any electronics related stuff to be available for 10 years? I think I've seen a few boards marked long-lifetime. I don't remember the details. At least one OS distro has a version marked long-lifetime, but I don't know how long that covers. What does the military do for this problem? What's the average lifetime of something like a radio in a military plane? How often do they get upgraded because the old ones are no longer maintainable due to unavailability of parts? What's the average lifetime of a fab line? Or even the max lifetime? (in case you are a big vendor with multiple fab lines for a particular technology) What's the typical lifetime of parts used in timing related gear? > Maybe that's the key.. think of it as an appliance. If it stops working, > and it's not because of something simple (power cord), then you're probably > better off building a new one from scratch than trying to fix the old one. > That is, the labor involved in "port to a new platform" might be > substantially less than "find old platform and install it in old box", if > only because things like tool chains tend to follow the latest hardware. A lot of that depends on the quality of the documentation you kept when you set things up. I've worked with guys who were good at making a big pile of kludgy gear jump through hoops. One of them was very good at writing down what he did. It doesn't have to be a fancy document blessed by 43 proofreaders, but it really helps to mention all the critical steps and/or explain the non-obvious reasons for doing things. I've gotten into the habit of making a checklist of what I have to do to install distro-X from CD and fix it up to do what I want. Every now and then, I want another box just like that one except... It isn't fancy, but it does have a line to remind me about each file that needs editing and what tools are used to set things up. Often there are chunks of code I can cut-paste. > Even if you kept the tool chain for your old platform, running it on a new > computer might be problematic. (recognizing that there are people out there > running IBM 1401 emulators on System/360 emulators on... but that takes > time too) It's not uncommon to archive the PC that has all the tools when a significant hardware project is released. Just put a big note on it and push it into a closet in case you ever need it again. (Setting up CAD tools is often quirky and hard to debug.) Again, this needs documentation. Suppose you want to make a simple one line change to fix a typo. What do you do to turn the crank and make the files you hand off to the next step? -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.