i860: Re: modern stuff

Chris Hanson cmhanson at eschatologist.net
Mon Oct 29 14:32:59 CDT 2018


They were used in some X terminals, so there were at least high level enough operating systems to support an X11 server.

  -- Chris

> On Oct 29, 2018, at 11:12 AM, alan--- via cctalk <cctalk at classiccmp.org> wrote:
> 
> 
> 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



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