Volumes listed by CUG catalog #

• Volumes 100-199: 1981-1986
  101-148: CP/M, many are specific to Z-80/8080/6800 CPUs
  149-199: CP/M and MS-DOS 2.0
  
• Volumes 200-299: 1987-1989
  MS-DOS predominates, less CP/M, some UNIX
  
• Volumes 300-399: 1990-1993
  MS-DOS, Unix, OS/2, some Atari and Amiga. First C++ volumes
  
• Volumes 400-499: 1994-present
  MS-DOS, Unix, and Windows. Many C++ volumes