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 ljw.me.uk The IBM 360/30 pagehttp://www.ljw.me.uk/ibm360
