If you think of IBM mainframe computers, you most likely are thinking of the iconic S/360 or the slightly newer S/370. But what about the 7070 from 1958? It had transistors! It didn’t, however, use binary. Instead, it was a decimal-architecture machine. You can see a lost video of the machine below.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/03/29/retrotechtacular-the-ibm-7070/