Jerome Fine replies: I also like to use the original hardware, but I also am a bit wary of how long the original hardware can last since I don't want to be directly involved in the maintenance other than swapping boards. So, as with the above answer, I also will start to rely on emulators. QUESTION: In general, how long would a seldom used system (about 2 * 5 hour sessions twice a week or about 500 hours a year) tend to last? I am referring to BA23 and BA123 PDP-11 systems to be very specific. The answer need not be in years, but in probable decades if that is the best way to approximate the answer. Namely, I am wondering if I can HOPE/expect 1 or 2 or even 3 or 4 decades of future use from a BA23 or BA123 system. Also, the VT100s and VT320s seem to be lasting. What about the terminals? Of course, the same sort of question can equally be applied to the emulator software - how long can a given application program be expected to run on the current PC hardware/ software environment. I suspect that the answer is much less, but at least software can be modified once with many copies easily made and distributed even more easily. But hardware, once it breaks, is often more difficult to fix and each system must be maintained individually, a much more difficult task and in the long run - 50 years - likely impossible. Comments on the question and all of the other aspects are very much appreciated. While I have a great deal of experience with software, my intuition about hardware is very limited! Sincerely yours, Jerome Fine