On the Cyber running NOS, we had XEDIT. And similar to your story, I routinely dumped 10 lines of context after each change. Whatever that command was, was hard

On the Cyber running NOS, we had XEDIT. And similar to your story, I routinely dumped 10 lines of context after each change. Whatever that command was, was hard coded into muscle memory to the point it was mostly automatic. The other nice feature was that you could do quick in place edits from the command line. Combination of ed and sed. Another aspect that impacted TECO on the PDP was the concept of paging the file in. The machine was limited enough that you as a user were responsible for swapping parts of the buffer in and out, which, while usable, was not a good user experience. When loading a large file TECO/vtedit would prompt “loading file xxx.yyy slowly”. And it was. In the labs, my friend and I would commandeer multiple terminals, with one of them being our file loaded in the editor. We’d constantly write the file out, but never exit. And by “large file”, I’m talking a 35K byte source file. It was a different time, to be sure.