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The Cray-1 Computer System (1977) [pdf]

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Re: The Cray-1 Computer System (1977) [pdf]

#71

Earlier quoted context omitted.

It looks really nice - but never understood the seating. Who came up with that?

It ensures the Cray is placed as the centerpiece of the room, not as mere equipment shoved on the wall

Probably they could achieve the same with circular construction but without the seats.

Re: The Cray-1 Computer System (1977) [pdf]

#72
post #20

Earlier quoted context omitted.

>how many times faster my iPhone 17 Pro Max is.. Sadly most of that power is not working for you, most of the time, but working against you, by spying, tracking and manipulating you. Bet that was not include in your sci-fi dreams in 70s..

I'd love to see you substantiate that - bet you can't.

I certainly can't. I'm running GrapheneOS.

Re: The Cray-1 Computer System (1977) [pdf]

#73
post #3

to deploy a 2nd hand Cray-1 at UQ, we had to raise the ex-IBM 3033 floor, it turned out the bend radius for flourinert was NOT the same as a water cooled machine. We also installed a voltage re-generator which is basically a huge spinning mass, you convert Australian volts to DC, spin the machine, and take off re-generated high frequency volts for the cray, as well as 110v on the right hz for boring stuff alongside.…

Cray-1 or Cray-2? IIRC Fluorinert was new with the Cray-2, while wikipedia suggests that the Cray-1 used a freon as coolant.

Cray old-timer here; 'nert was definitely Cray-2 and later. In the Cray-3 it was turned into mist.

Re: The Cray-1 Computer System (1977) [pdf]

#75
post #58

Compare this to modern system: we could fully simulate this kind of slow computer in real time, I would guess, with all the wheels, clockwork and mechanics as well as logic circuits with full electricity. Deciding the simulation level would be a bit challenging - is this an atomic, an electron or more common sense simulation -; still I think the simulation would work as well as this kind of document.

Absolutely not on the electrical level. ISA emulation, probably, maybe, though these Crays are not IEEE machines so you have to actually fully emulate the floating point operations, instead of punting them to the FPU. That may make getting hundreds of MFLOPs on difficult.

Re: The Cray-1 Computer System (1977) [pdf]

#76
post #3

to deploy a 2nd hand Cray-1 at UQ, we had to raise the ex-IBM 3033 floor, it turned out the bend radius for flourinert was NOT the same as a water cooled machine. We also installed a voltage re-generator which is basically a huge spinning mass, you convert Australian volts to DC, spin the machine, and take off re-generated high frequency volts for the cray, as well as 110v on the right hz for boring stuff alongside.…

I used a Cray C-90 and T3D 256-core machine from 1995-1999. The T3D used commodity Alpha 21164, and was already behind the T3E when we got it (Cray refurbished.) By the end it was outclassed by an SGI Oxygen box with 8 CPUs. I’d already ported a lot of software from SunOS and HP-UX to Irix and Unicos (Cray) and it was easy to move it to Linux in the end.

You means SGI onyx? The cool looking purple one?

Re: The Cray-1 Computer System (1977) [pdf]

#77
post #4

The CRAY-1 was so ridiculously ahead of its time that it took until the Pentium MMX (1997) for “ordinary” computers to catch up to its raw performance. That’s 20 years or about 10,000X the available VLSI transistors via Moore’s Law.

> The CRAY-1 was so ridiculously ahead of its time that it took until the Pentium MMX ...

You'd need a different comparison to show how the Cray-1 was special. If the comparison is to single commodity CPUs, like the Pentium MMX, you could make much the same comparison for many mainframes and supercomputers. Several supercomputers in the 1980s exceeded 1 GFLOP, for example, and it wasn't until the 2000s that you could get commodity CPUs with that performance.

Re: The Cray-1 Computer System (1977) [pdf]

#78

I quickly skimmed the instruction set and did not see anything resembling a sub-routine call or branch and link instruction. Did I miss it?

The "R exp" is subroutine call (which saves return address to register B00), and I believe "J Bjk" is the subroutine return.

The Cray-1 didn't have a hardware stack, so subroutine call is basically just jump there and back, using a register for the return address rather than pushing/popping it to/from the stack.

Another oddity of the instruction set that stands out (since I'm in process of defining a VM ISA for a hobby project) is that the branch instructions test a register (A0 or S0) rather than look at status flags. In a modern CPU a conditional branch, if (x Gemini explains this as being to help pipelining.

Re: The Cray-1 Computer System (1977) [pdf]

#79

I quickly skimmed the instruction set and did not see anything resembling a sub-routine call or branch and link instruction. Did I miss it?

Subroutine calls are for the weak :)

There's some more detail here: https://ed-thelen.org/comp-hist/CRAY-1-HardRefMan/CRAY-1-HRM...

The following quote gives some sense of how "manual" this was:

> "On execution of the return jump instruction (007), register Boo is set to the next instruction parcel address (P) and a branch to an address specified by ijkm occurs. Upon receiving control, the called routine will conventionally save (Boo) so that the Boo register will be free for the called routine to initiate return jumps of its own. When a called routine wishes to return to its caller, it restores the saved address and executes a 005 instruction. This instruction, which is a branch to (Bjk), causes the address saved in Bjk to be entered into P as the address of the next instruction parcel to be executed."

Details were up to the compiler that produced the machine code.

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