Thursday, February 20, 2014

Good Bits

Hex nut driver bits can be very useful for opening up vintage PCs and not quite so vintage, especially those made by IBM.  Here are some bits and the screws they can more easily unscrew in most instances than a standard slotted screwdriver.

3/16" - Expansion card retention screws for IBM PC, XT and probably the AT, XT/286 and Portable, Expansion card retention screws for the Tandy 1000/A/HD/SX.  Drive mount and system board retention screws for IBM PC & XT, probably others.

7/32" - IBM Model M Keyboard screws, probably Unicomp Keyboards as well.  Needs a long barrel bit to fit inside the three of the four holes for the screws.

1/4"- External case screws for the IBM PC, XT and probably the AT, XT/286 and Portable, Internal case screws for Tandy 1000s.  IBM Model F PC and probably AT screws.  System board screws for Tandy 1000s.  Floppy disk drive mounting screws for IBM PCjr.

Later, more generic PC cases can still use the 1/4" and 3/16" bits, even though they have Phillips-screw heads, as they are still using hex heads.  Sometimes in-between bits like 5mm and 6mm can also come in handy, the former especially when trying to screw in port standoffs.  


  1. Are you saying the bronze/copper colored motherboard stand-offs are 5mm? I was thinking of getting a hex driver just for those...

  2. The ones that hold in the DA, DB and DE connectors for game, parallel and serial ports should be 5mm, but you will need a really thin tool to tighten them. Not positive about the ones that screw into the motherboard, they may be larger. Bring one with you when you go to the store.