Re: How many times must Apple make such DRASTIC architecture changes?

[Eric Smith <eric@brouhaha.com>]

Paul Schlyter <pausch@NOSPAMsaaf.se> writes:
> For almost 30 years.  I believe the first 64-bit os was COS (Cray OS) for 
> the Cray-1 supercomputer, released in 1976.

Hardly!  The IBM 7030 Data Processing System, also known as "Stretch",
was introduced in 1961, and there were at least three different operating
systems for it.

> It definitely didn't have a full 64-bit address space,

The 7030 had an address space of 2^24 bits, or what we would now call
256KiB.

> but the hardware did have a 64-bit word size.
> And it was word addressable

The 7030 had 64-bit data words, and was bit-addressable for everything
but instructions, which had to be 32-bit aligned, and floating point
operands, which had to be 64-bit aligned.

The 7030 was the first computer to use deep pipelining, speculative
execution, and many other features we take for granted in modern
processors.

Eric

http://www.brouhaha.com/~eric/retrocomputing/ibm/stretch/