Royal McBee / Advanced Scientific Instruments (ASI)
The LGP-30 was the first machine with a Return Jump instruction. The index register first appeared in a computer made by Ferranti company of England. I think it was the Ferranti Atlas computer, but it was called a "B-Box," short for Bias Box, a descriptive name if I ever heard one.
That was a great article about the RPC-4000. The LGP-30 and the RPC-4000 were my first and second commercial computers. They were sold and serviced by Royal McBee. The LGP stood for Librascope General Purpose-30 (there was a LGP-29 and a LGP-21 if I recall correctly, but they were duds) and the RPC-4000 stood for Royal Precision Computer-4000. An RPC-9000 was announced at the same time, but it also was a dud.
Interestingly enough, about a year into the RPC-4000 program, I quit Royal McBee to go to work as the first Field Engineer for a new company in Minneapolis, named Advanced Scientific Instruments, Inc. They had delivered their first machine to Goddard Space Flight Center, near Washington, and needed someone to take care of it. They also had orders for two more in the area, one at Aberdeen Proving Grounds and one at The Army Chemical Center. The President of the company was a guy named Francis Alterman. In my six or seven months with that company I watched as he "managed that company out of business." When ASI went belly up I had moved on to BNL again to the Computer Systems Group. A couple months later I saw in the news that General Precision had a new President, Francis Alterman, and within a very few months they too were out of business.