Modifications:IBM Model M
The venerable IBM Model M has a long history, a strong following, and a good set of mods to go with it.
Nut and Bolt Mod
If any work needs to be done on the innards of the keyboard assembly, a so-called nut and bolt mod is usually required. The plastic barrel frame that supports the key caps is attached to the steel back plate with plastic rivets. The rivets are just pins of the frame that protrude through the back plate and are melted in a special jig. Over time, the barrel frame become brittle and the rivets break off and separate.
This modification entails removing the old rivets, drilling holes in the barrel frame for small machine screws, and reassembling.
Cracked Barrel Frame Repair
Another failure that is common is cracking of the barrel frame. The frame is molded flat. Between each row of keys is a channel that allows if to flex to the curve of the back plate. As the frame becomes brittle over time, cracks start to form along these channels. Broken rivets can promote frame movement while typing, which accelerates this process.
It is possible to repair a cracked frame or replace it with a new one from Unicomp.