CaptSunset wrote:The Library Board wants to upgrade the whole shebang, but are stalled out by the dominance (cost) of Apple vs (the ongoing aggravations of) win10.
it is difficult to justify Apple from a cost point of view. The OS/X software is based on Unix and retains many of the advantages, however, the hardware is expensive and not maintainable: If the CPU breaks you throw away the monitor too, of the monitor breaks then out with an otherwise working system. Also, computers don't seem to be Apple's main line of business anymore. Having said this, I'll admit I have an iMac and was able to replace the HD when it broke. On the other hand, it sure doesn't work for swapping monitors between computers or connecting one to a laptop.
You mention coal powered desktops, but fail to state specifics of how much RAM each old computer has. If the desktops in question have 2GB RAM or more they will outperform any model of Pi on memory intensive tasks like web browsing.
I know some libraries could be running Windows 95, however, if you are running XP and dealing with the end-of-support issue you may want to check whether the current hardware can be switched to one of the well-supported Intel-compatible Linux distributions such as Ubuntu, Arch or Mint. Typical 7 to 8 year old Intel hardware outperforms any Pi when browsing the web. Independent of the computers, new keyboards, monitors and mice will make everything look new.
When it comes to new hardware, there are small and cheap Intel compatible machines with 8 to 16 times the RAM of the Pi. These could be setup with Linux to avoid the issues with Windows 10. An upgradable machine with 8GB of RAM can be expected to outlast a non-upgradeable machine with 1GB by a factor at least 3 fold. The problem is finding a vendor that can be trusted to set up and maintain a well functioning set of Linux computers. Of course you can do it yourself and there are online communities for Ubuntu, Arch, Mint and other Linux distributions that are helpful. One fall-back position that minimizes risk is to buy computers licensed to run Windows 10 and revert back to Microsoft if needed. However, if you think a Pi running Linux would be sufficient, there is little chance that Intel hardware running Linux would fail to satisfy.
The Raspberry Pi is interesting because of the super small size and accessible GPIO pins. It can be used as a desktop computer, but was not really designed to be one. An advantage of the Pi is that Linux is essentially the only operating system people use on it. This has led to this small but focused community with Linux expertise that can help solve problems. It is also cheap, so if a Pi experiment fails, toss the Pi but keep the new monitors, keyboards and mice. Good luck!