66 - reserved for user interrupt
 66 - Adaptec controllers - DRIVE 1 DATA
 66 - Data General DG10 - MicroECLIPSE COPROCESSOR INTERFACE
 66 - Nanosoft, Inc. TurboNET - NETWORK PROCESSING ???
 66 - Pdisk by Scott Garfinkle - Overwritten for Hard Drive information
 66 - Microsoft Windows VITD.386 Virtual Interval Timer
 6601 - BitFax Scheduler - SET MODE???
 6602 - BitFax Scheduler - SET MODE???
 6603 - BitFax Scheduler - SCHEDULE FAX TRANSMISSIONS
 6604 - BitFax Scheduler - GET STATUS???
 6605 - BitFax Scheduler - CONVERT FILE AND SEND FAX
 6606 - BitFax Scheduler - SET MODE???
 660688 - John W. Ratcliff (The IBM Digitized Sound Package)
 660689 - John W. Ratcliff (The IBM Digitized Sound Package)
 663345 - BitFax Scheduler - REMOVE TSR FROM MEMORY
 66FFFBBXFFFB - MicroHelp Stay-Res Plus - ???
 66FFFEBXFFFE - MicroHelp Stay-Res/Stay-Res Plus - UNINSTALL
 66FFFFBXFFF0 - MicroHelp Stay-Res Plus - FIND PROGRAM NAME