[rescue] Mainframe on eBay

[Sridhar Ayengar]

Jonathan C. Patschke wrote:
>>The characteristic required in the F50 is the secondary PCI bus.  Just
>>make sure the 7043-150 has a secondary PCI bus, and plug it into one of
>>those slots.
> 
> I believe both the -140 and the -150 have secondary PCI buses.  They're
> connected to the system via a PCI-PCI bridge connected to the primary
> bus.  Do the buses need to be peers, or will that work?

Actually, I think they specifically *can't* be peers, so it should work 
fine.  Just make sure to plug into the secondary bus.

>>Even on the F50, you have to plug into the secondary slots.
> 
> Odd.  Is the P/390 a bus-master or DMA-heavy device?  I'd thought that
> it would be relatively well-behaved because it has separate memory.  Or
> does the ARCTIC-960 card receive commands from the P/390 instead of the
> host system?

I'm pretty sure it's busmaster.  However, it is well known to be one of 
the *most* finicky devices out there.  It's pretty heinous in that 
regard, actually.  I've found that the only non-IBM PC chipset the P/390 
PCI works in is the i450NX.  Pretty rare chipset, on the grand scheme of 
things.

And yes, I believe that the ARTIC is communicated to directly.

> BTW, this isn't exactly up your alley, as you're a mainframe guy, but my
> new boss was the lead architect for the S/32, S/38, and RT/PC projects.
> I definitely plan on picking his brain sometime. :)

I've played with RT's somewhat.  8-)

I know next to nothing about AS/400's and their predecessors.  Except 
that they're EBCDIC and use shared-memory processes which is just 
strange enough to warm my heart.

What's your boss's name?

Peace...  Sridhar