PC532 Motherboard. ----------------- Approximately 2550 holes. On Drill hole drawing the following Letter designations refer to: Letter Hole Size ------------------------------------------------------------------- A 0.038 inch Finished size (component holes) B 0.060 inch Finished size (ibm power connector) C 0.160 inch FInished size (mounting holes) D 0.028 inch Drill size (via holes) F 0.060 inch Finished size G 0.090 inch Finished size