Vintage Computer Festival wrote:
1. Who invented the Index Register and about when?
3. What was it originally called?
4. What computer first used one?
A:
1. The British invented in in about 1957 or 58.
2. It was originally called the "B-Box" for
"Bias Box".
3. I believe it was first used in the Ferranti Atlas
computer.
A little earlier. The Manchesetr Baby machine first ran in 1948. It had
no B-lines, but they were added before the final Mark I was specified to
Ferranti for commercial production. Ferranti delivered the first Mark I
to Manchester in Feb 1952 a few months ahead of the first Univac
delivery in the US.
B-lines, because the A-line was the Accumulator, the C-lines were
control registers : the sequcnce control reister (PC) and the current
instruction.
see :
http://www.computer50.org/mark1/FM1.html
-- hbp