Good question! https://www.nytimes.com/2016/06/02/insider/1966-2016-the-las... mentions an IBM 1620 being installed, but that was all the way back in 1964. The 1978 coverage of switchover day http://timesmachine.nytimes.com/timesmachine/1978/07/03/1108... mentions that the Times had spent $17 million each year over the past three years, and that the actual typsetting machine was a Letterflex. But no details of the computer software or hardware, AFAICS.

They showed a Data General nameplate at one point. The panels with blinky light bulbs and a button for "IPL" suggest IBM. Some of the PC boards they showed had 7400 series TTL, and others raw transistors in metal cans. Those might have been just stock footage.

There was another panel with somebody flipping what looked more like Digital Equipment Corp. switches. Normally, you would do that only when booting the machine: you would put in a program by setting switches for a few words in memory -- set, store, set, store,... -- and run that to read in and run a paper tape that itself had just enough code to read and run a boot sector from disk, and off you went.

The notion of buying expensive, read-only memory useful only when you boot was absurd. (You needed the paper tape reader anyway.)

Often there was a stick with notches for the switches. You would flip all the switches up and push the stick against them, pushing some down, and store, then rotate the stick and do it again. Cheap ROM. The program to read paper tape was very short.

I wonder too. There seems to be some element of WYSIWYG as the font can take different sizes. For 1979, it is pretty advanced. Xerox Bravo was doing this a few years earlier but Xerox was well in advance of its time.

It appears to be caps and no caps to me.

In the video, 22:15.

Thanks

No idea on the OS, but I'd venture a guess that the text editor was some bespoke application made specifically for the industry, and if you weren't in it, you've never heard of it.