[rescue] IBM on ebay

[Sridhar the POWERful]

On Mon, 13 May 2002 dave at cca.org wrote:

> >> Aside from the obvious performance issues, wasn't that AT/390 thingy
> >> actually not fully compatable?
>
> >There was no AT/390.  The AT/370 was a 2 ISA board mutant that implemented
> >most of the 370 instruction set in microcode on a modified mask 68000, and
> >emulated some of the rest with a vanilla 68000.  It didn't have full
> >support for priv instructions and only ran a single user version of
> >VM/CMS.
>
> Ah....
>
> Did it emulate the IO processors?

No, but the channel cards did.

> Did IBM fab the mutant 68K, or did Moto do it?

No idea.

> >The smallest /390 is probably the P/390 or R/390, essentially one-card
> >PCI or microchannel implementations of the 390 arch.  They make
> >respectable development systems, I would have loved to have had one when I
> >was doing MVS application development.
>
> Interesting.
>
> So you could put a 390 CPU in an RS/6000, and use the POWER CPU as
> an IO processor for the 390... Deja Vu!

You can even offload the I/O to emulated channel processors running on
i960's on separate cards.

Peace...  Sridhar

--
"How do you fight such a savage?"

"With heart, faith, and steel.  There can be only one."
	-MacLeod and Ramirez, "Highlander"