i860: Re: modern stuff

[alan at alanlee.org]

I know i960 is a very different beast, but was there ever any high level 
OSs that ran on it?  Or was it pidgin-holed as a high speed embedded 
processor for storage controllers and NICs?

I picked up a cache of i960 CPUs a couple years ago and they speak to me 
in tongues every time I pass by the shelf.

-Alan


On 2018-10-29 12:56, Ken Seefried via cctalk wrote:
>> the i860 found at least a little niche on graphics boards, so somehow
>> not a complete failure ;-)
> 
> I'd be mildly surprised if Intel ever made enough from selling i860s
> as GPUs to cover the cost of developing and marketing them.  At the
> time, Intel was pushing them as their RISC processor, and put a lot
> into the program.  Going to take over the world and all that.  Maybe
> not a 'complete' failure...just mostly.
> 
> From: Chuck Guzis <cclist at sydex.com>
>> On 10/26/18 6:10 AM, Gordon Henderson via cctalk wrote:
>> 
>>> However it was a royal PITA to code for although a 32-bit CPU, it 
>>> would
>>> read memory 64 bits at a time (actually 128 IIRC to satisfy the 
>>> cache),
>>> with half that 64-bit word being an instruction for the integer unit 
>>> and
>>> half for the floating point unit, so you effectively had to build a
>>> floating point pipeline by hand coded instructions, so 8 (I think)
>>> instructions to load the pipeline, then each subsequent instruction
>>> would feed another value into the pipe, then another 8 at the end to
>>> empty it. Great for big matrix operations, rubbish for a single add 
>>> of 2
>>> FP numbers.
>> 
>> My impression of the i860 was that it might have been fun for about 2
>> weeks for which to code assembly, but after that, you'd really start
>> looking hard for an HLL to do the dirty work for you.  While there's a
>> sense of accomplishment over looking at a page of painfully
>> hand-optimized code that manages to keep everything busy with no
>> "bubbles", you begin to wonder if there isn't a better way to spend 
>> your
>> life.
> 
> It wasn't fun for the whole 2 weeks.  And the i860 is Yet Another
> example of Intel claiming their compilers were going to be so smart
> that all the architectural complexity/warts will never be noticed.
> Wrong, and they didn't learn and said the same thing about Itanium.
> The interrupt stall issue that Gordon pointed out was so bad they were
> basically relegated to single-task software in the end.
> 
> KJ