Hacker News Reader

Alas, it seems we haven't been able to locate the source or binary for this important artifact. It would have been wonderful to have this preserved and a simulator, like we have for the Alto and countless IBM machines, etc.

Failing that, I'd be happy to just have a reimplementation, that's a faithful as possible to the original.

View on HN

As far as I know, that's correct. Furthermore, the TX-2 it ran on was a one-off machine, and was changed over time, so the same instruction might do different things before and after hardware changes. I don't know of a description of the TX-2 at any point in time sufficiently complete to write a simulator, much less at the particular time SKETCHPAD was being built.

Presumably it would be somewhat simpler than the PDP-1 simulator, and perhaps could even use the same scope simulation code — Norbert Landsteiner tells me that simulating the visual effects of the scope tube was the hardest part of writing the PDP-1 simulator.

Sketchpad listing at the Computer History Museum:

http://www.computerhistory.org/collections/catalog/102726903

Oh cool, thanks for pointing that out. It looks like it would be a major undertaking making a working piece of code from that.

Reply on news.ycombinator.com