i860: Re: modern stuff

[Rob Doyle]

I'm aware of some airborne (avionics) computers that used i960s.  There 
were Mil-spec versions available.

I believe the i960 really only found a niche in embedded applications. 
If I recall correctly, the i960 became available at about the same time 
as the 80386 but was less expensive.  At the time, you couldn't afford 
to put a 80386 in an embedded application because Intel was getting 
artificially high prices due to PC-based pricing.

Intel later tried to address the embedded market pricing issues by 
releasing the 80376 and later the 80386EX.  Both those products were 
munged so they couldn't run DOS and that kept their pricing model intact.

The i960 did have a user mode and supervisor mode - so it could have 
supported a 'real' OS.

Rob.

On 10/29/2018 11:12 AM, alan--- via cctalk 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
>