
Without too much Googling I found the "IPv6 Buddy". It looks like a numpad re-mapped for hex input. I might make one for fun.
I've seen many variants over the years that perhaps place A-D on a column to the right of the numpad or whatever.
So, if you have a vintage hexadecimal input device, or whatever, please share it here!
Yes, I already know about the HP-16C as well.