dtgreene: Windows 3.1 (and 95/98/ME) were horribly buggy and unstable. Yes, you might get decent performance, but you would also get random crashes. DOS was not much better; it was also a buggy mess.
What on earth were you doing with them to get them unstable? OK, MS-DOS was not 4DOS, Linux or Netware, but it wasn't that unstable. As long as you didn't have any leaks since 16-bit OS was a bit bad at memory handling.
dtgreene: Or, anyone who used Linux in the early days will remember how much more stable (in terms of not crashing) it was than the mainstream proprietary operating systems.
And completely immune to viruses. Remember the love letter virus? I don't. I read the mail, warned the person from whose email account I got it and then deleted the mail.
dtgreene: I'm wondering if there'd be a way to set up a Raspberry Pi, or even an ESP8266 or other microcontroller, so that, in response to an SSH request, it would:
* Check if a certain computer is awake. If not, wake it up.
* Regardless of whether the computer was awake when the connection was attempted, forward it to that computer.
Yes.
Write a script that pings the computer you want to check. But I don't really see the point of RPi in between here. You can do that directly from whatever is sending that SSH request.
But you could do so much more with RPi. For example: get a controller for leds and build some buttons. A LED for each computer you have, connect to controller, controller to RPi, connect the buttons to the IO (or to the controller if you have a lot of computers). Set the RPi to periodically ping your computers. If there is a response, keep the LED on for that computer. If no response, turn the LED off. The button can be tied to a script that when pressed, it does the check and if there is no response, send a magic package, if there is a response, send a shutdown command. Then you can have a plate on your wall with LEDs showing you which computers are on and which are off, and a button under each LED so with a simple button press you can toggle the on/off state of each computer. If you don't like that you have the USB-cable and the network cable coming down from the plate, use WIFI so you have only the USB-cable for power.
Or, if you like the LEDs but don't want big physical buttons, forget about the buttons. Just buy an IR-receiver and connect it to the IO (check the voltages, you might need a resistor in between). Raspbian comes in-built with LIRC. Then just program any of your remote controls to do the same thing. This way you can have the LEDs on your wall with the IR-receiver so you can easily see which computer is on and which is off, and use a remote control to turn each of them on or off.
edit: if you don't have any extra remote from any old TV, VCR, DVD player, whatever, you can get those from flea markets, used electronics shops or eBay for pocket change.