Details about IBM's early 'scientific' computers

Lawrence Wilkinson ljw-cctech at
Tue Nov 14 16:40:17 CST 2017

On 14/11/17 18:20, Chuck Guzis via cctech wrote:
> It's always struck me how revolutionary (for IBM) the change in
> architecture from the 700x to the S/360 was.  The 709x will probably
> strike the average reader of today as being arcane, what with
> sign-magnitude representation, subtractive index registers and so on.
> The 7080, probably even more so.  But then, most of IBM's hardware
> before S/360 had its quirky side; the only exception I can think of,
> offhand, would be the 1130, which was introduced at about the same time
> as the S/360.
I think the 360 marked the change from hardware-driven development to
software-driven. The 'arcane' architectures would have maximised
performance for a given amount of hardware, and programmers were
relatively cheap. But the 360 reversed that, hardware was now cheap
and didn't need to work at 100% efficiency, but software development
was expensive so writing and re-writing needed to be minimised.
> The S/360 was a breath of fresh air for IBM.
Which is why it's still around today, even if the name has changed.
> --Chuck
> Sent from my digital computer
Lawrence Wilkinson                          lawrence at
The IBM 360/30 page

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