classic operating systems

Depends on how you mean that. Is that freely available, or available at a cost? I believe the source code is available for most DEC OS's including VMS if you want to pay for the license. Some DEC OS's such as RT-11 come with most if not all of the source. Others have already pointed out UNIX and CP/M stuff available. Zane | Zane H. Healy | UNIX Systems Adminstrator | | healyzh(a)aracnet.com (primary) | Linux Enthusiast | | healyzh(a)holonet.net (alternate) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | and Zane's Computer Museum. | | http://www.dragonfire.net/~healyzh/ |