I wonder if the keyboard in question is actually different at the hardware level -- in the sense of transmitting different scan codes -- from any of their other

I wonder if the keyboard in question is actually different at the hardware level -- in the sense of transmitting different scan codes -- from any of their other models, or if the difference is simply cosmetic (different keycaps). Either way, you could do the same thing in software, but I suspect that learning the layout (which is even more foreign to most people than Dvorak) would be hard without the keys. Still, you could probably get a spare set of keycaps or just a cheap keyboard and write the glyphs on there with Sharpie for the time it took you to learn. Still, it's kinda neat. Also, opening saved APL files and displaying them correctly (with the modern Unicode equivalents) is probably a good test for anyone writing an editor these days. I assume it must have used its own high-ASCII codepage to store the uncommon characters.