[cctalk] Re: i860 vs. i960 WAS Intel's i860, Cray-On-A-Chip

[Paul Koning via cctalk]

> On Sep 23, 2022, at 11:50 PM, Ali via cctalk <cctalk@classiccmp.org> wrote:
> 
> I always thought the i960 was an upgrade to the i860 (sort of like i386 to 
> i486 upgrade). However, based on the info on wiki it seems as if the i960 
> actually came first and although a RISC chip it was in no way in the same 
> league as the i860. Anyone can clarify or verify this?

I have very bad memories of the i960 from my time at Chipcom.  The main memory 
I have is that it uses an utterly misdesigned queue based I/O architecture, 
full of race conditions.  I think it's the same "design" used in the much 
maligned i82586 Ethernet chip.

The odd thing is that others had done correct and race-free queue designs a 
decade or two earlier, but Intel never showed any sign of design competence and 
it is just an example of this that they screwed up I/O queues so badly.

        paul