FYI -- Revisit the most usable/least secure timesharing system ever made! https://github.com/PDP-10/its ITS, the Incompatible Timesharing System, is an operating system for the PDP-10 computer family. It was created by hackers at MIT in the 1960s. The MIT site was shut down in 1990, but enthusiasts continue to operate ITS systems to this day. About this project This repository contains source code, tools, and scripts to build an ITS system from scratch. The goals are: To provide an automated build from start to end. No user invervention is necessary. To check which programs have source code, and which programs are missing source code. To ensure that we know how to build all programs. In many cases we can just invoke MIDAS, but some require the use of DDT. To update programs with the latest bug fixes and enhancements. To be able to set configurable options across the whole system, such as host name, IP address, hardware devices. The build currently runs on the SIMH and KLH10 emulators. Of course, we'd be delighted to test this on a real KS10. Usage To build ITS with this repository, you need some tools installed: make, C compiler, and expect. Ensure all submodules are checked out, and then type make EMULATOR=simh or make EMULATOR=klh10. This will leave built files in the out directory, one of which is a disk image with ITS installed. To start ITS, type ./start. If you see KLH10#, type go and Enter. When you see the DSKDMP prompt, type its, press Enter, and then ESC g. Eventually, you will see SYSTEM JOB USING THIS CONSOLE. You are now ready to log in, so type Control-Z. See doc/DDT.md for a list of useful commands. When done, shut down orderly by typing :lock and then 5down. To install your personal user files, add a subdirectory under user with your files inside. They will be copied to ITS. The directory name is limited to six characters, and file names must have two six-character parts separated by a period. Here is an overview of the repository: bin - PDP-10 binary files necessary to bootstrap the system. build - build scripts. doc - documentation, most of which appear in the INFO system. src - source code for ITS and all programs. tools - build tools. out - build output. user - optional user files installed in ITS.