Look at the original forum post for details.
http://www.computercraft.info/forums2/index.php?/topic/23066-gps-minimap-v139-graphical-minimap-for-your-pda-advancedregular-see-other-clients-on-the-screen/

Basically,
this is an advanced GPS-based minimap for ComputerCraft's pocket
computers and turtles. If a GPS server is within range, it will work.
Otherwise it has very limited functionality...

This can run on
both advanced computers and regular computers, and they both look just
as good, but advanced computers can use the mouse.

Get it with
pastebin get x9ajKSc0 map