[mikewarot]

First of all, how would they talk to it? You'd have to give them an RPI5 with serial console enabled, and strict instructions not to exceed the 3.3 volt limits of the I/O. Now it's reasonable that you could generate NTSC video out of it, so they could see on the screen any output.

When you then explained it was just bit-banging said NTSC output, they'd be amazed even more.

[dottedmag]

Serial port

Cray 1 was released 1975, teletypes were old tech at that time.

[Aardwolf]

Give it also an hdmi screen and usb keyboard, what more do you need to type code and see the result