Tell me what you think.
In this science-fiction universe, AI where outlawed after a nasty war, the Butlerian Jyhad, and so, some alternative had to be be done... The Mentats. Psychic, living computer brain kinda guys.
So, if you have psionic, maybe...
OR similar but a dash different, the Metroid solution; Brains in jars.
I may be wrong, but did you have a post a while back about adding facebook to the game... you had a magic book, with a face on it... why not just have it on the computer... why not just play in modern times?
I don't get it, could you tell us a bit more about how this works
But, I see absolutely no reason you couldn't introduce computer technology into a D&D campaign, considering that even the stupider examples of things like Dragons, Aboleths, Illithids, and Beholders have intellects on a par with legendary human geniuses, and many of these creatures have come from other worlds and other dimensions.
And, there is the way that the Eberron setting assumes that Magic has powered an equivalent of the Industrial Revolution, with magic-powered automatons, trains, and so on... why not magically-powered computers? That wouldn't be even remotely the goofiest thing to ever appear in Dugeons & Dragons - don't believe me? (link)
I do suggest making the computer technology something very different from modern electronics, with no recognizable equivalent to Windows or Skype or anything like that.
Perhaps use Giger's Biomechanical technology as an inspiration, or something steam-punk flavored at least.
Ultimately a modern computer is nothing more then a device that can calculate really fast and precise, and that's connected to a network of millions of others of its kind. A brain in a jar with a psychic connection to other brains all over the world would simulate a computer hooked up to the internet perfectly.
Zombie/skeleton mice given specific instructions. A series of weighted pads that they stand on that cause the other pads to rise up or down. Instructions = stand on pad if you see it come up.
Idea is fleshed out lots further elsewhere if people like it. (also not my own)
"The Turk", supposedly a clockwork chess-playing robot (link) - it turned out to be a hoax, but in D&D anything could be possible.
The "Antikythera Mechanism", thought to be an ancient astronomical computer using an unexpectedly advanced lost technology (link).
Alas, my download quota is exceded and I cannot view the video.
Are you able to see it now?
I'm reminded of ICP's "miracles" song...
But there's lot of ways you could go about this... one way I might try it, is the classical "alchemist table" method. A computer incorporates all four elements in it's design.
It's boarded down by earth. (Stone, marble, or some other ard material for a monitor.)
Generated by air. (Lightning, "force", "sonic" energy.)
It conducts heat, (fire) which uses a minor magic item as a coolant, to deal like one ice damage to someone who might touch it and hurt themselves. (Fans.)
You could just say crystal balls and other divination tools are practical fantasy forms of computers.
You could even justify it by saying they set up large beacons like cellphone towers, and these beacons allow you to make from one connection to another these magical/mechanical devices. These pillars could generate energy you need to send and receive information, maybe be responsible for transmitting like satelites and phonelines... That's the fun thing about fantasy. It doesn't have to be completely based on fact and "the rule of cool" first and foremost applies.
It's not to have a hint of realism... but a few inconsistencies here and there won't hurt.
Like land mines.
Ming china had them... and rockets of sort.
See also the novel Pavane by Keith Roberts (wikipedia: en.wikipedia.org/wiki/Pavane_%28novel%29)
Remember there is no Computer greater than the Human Brain so if you stick a hundred people in a room on a 10 person x 10 person matrix and have them each look at the colour of light comming through an individual periscope above each desk where they sit from (the ultimate observatory) and push a coloured block down to describe whether the pixel is black or white out of a ten bit x 10 bit wooden grid you have a 100 bit imaging engine which can be used to recieve an optically transmitted image.
Another room Identical to that will recieve the second pulse and both matrix are moved to a third room where the bit of one grid is pushed through the second and if Grid A & Grid B are both True Multiplication occurs...
So you see Maths on a large computational scale can be conducted using a massive calculation labour force. So If you think the Gnomes have a Computer that allows them to do calculus then it could just be a room full of Gnomes employed in a repeating task which in the large scale become a mathematical function that tells them howmany turns on the sluce gate flywheel are needed to allow fifty megalitres an hour to flow through a sewer.