From: "M. Edward (Ed) Borasky" <znmeb@...>
Date: 2007-07-21T12:49:12+09:00
Subject: Re: Taking the bull by its horns [was background]

John W. Kennedy wrote:
> Morton Goldberg wrote:
>> That's pretty complete. I've never read a history of IBM -- I was
>> going entirely from my memory of working with early IBM computers and
>> the oral tradition transmitted me by the many IBM employees I have
>> known over the years. BTW, you omitted the 1130, which I remember as
>> small  scientific/engineering machine roughly contemporary with the
>> 1620. But we seem to have determined my memory isn't to be trusted. So
>> where do you place the 1130?
> 
> From a marketing viewpoint, but not architecturally, it was the
> follow-on to the 1620, and the 1800, which had mostly the same
> instruction set as the 1130, was the follow-on to the 1710. (There was
> also a 1500, which was designed for CAI applications.) But the 1130 was
> post-360 -- IBM's first admission that the 360 couldn't handle every
> niche -- so I didn't include it.
> 
> The 1620 and 1130 were both noted for their omissions. The original 1620
> required an addition table and a multiplication table to be loaded by
> the operating system, or the arithmetic opcodes wouldn't work. This is
> why the 1620's code name, "Cadet", was elucidated by wags as "Can't Add,
> Doesn't Even Try". The later, advanced models didn't need the addition
> table, but still needed the other.
> 
> The 1130, on the other hand, was famous for its I/O facilities, which
> were comparable to systems of the early 1950s. For example, the console
> typewriter required the operating system to:
>    read each stroke from the keyboard as a 12-bit code,
>    translate the 12-bit code from a punched-card column to EBCDIC
>      (the keyboard came straight off the 029 keypunch),
>    translate the EBCDIC code to a code called Tilt-Rotate code, and
>    send the Tilt-Rotate code to the "golf ball", to print the character.
> 
> 
Ah, the 1130 -- the computer IBM named after lunch time. :)

Of course you know that the 1620 didn't have an adder. *Everybody* knows
that. Well ... the 1130 didn't have an adder *either*. It did adds using
shifts, ANDs and XORs. Seriously. IIRC the 1800 *did* have an adder.