Re: Off-the-shelf Ethernet in AS/400? -- MIDRANGE-L

Hi Mark (and others),

when Gigabit Ethernet was reaching reasonable prices in the PC market, a
customer asked me to install an ethernet feature in his 620 ...
He said he already  bought everything which is needed to be put in .
When I arrived there, he mentioned that he got an extremely good price
for some DLink Gigabit PCI cards and was very happy with the lots of
money he saved from the IBM gig-eth feature for the AS/400.
His face went nearly white when I told him he was on the wrong track !
I have never even thought of this before, but then I was technically interested.
Ok, to shed a little light on this:
If you have a closer look at (for instance) the PCI 10 MBit Ethernet Controller
FC 2723 you will see a lonely AMD Chip and some (little) other logic.
Mainly, this is the same as used in PCs. Some of  the other logic chips on the
planar board(s) (say: mainboard on PC-terminology) are standard PCI-logic
as well.  BUT: this is done to save costs in chip design only, the main 
difference
is microcode (say: firmware in PC terms). IBM uses standard chips for
PCI glue logic, some tape controllers and even the high-speed RAID controller
(the most sophisticated on the market) include some bread-and-butter chips
from "standard" logic manufacturers.
A not too small AS/400 system has a complete different bus-design as a normal
PC, it normally has several completely separated PCI busses, which are 
controlled
by an own controller dedicated to that bus only. Obviously, a different 
microcode
is needed to get this running. This gives a much higher bandwidth and controls
the IOPs more effeciently as compared to a wintel-machine where
all the control has to be done by the (normally one central) CPU-chip.

So: forget about cheap PCI-cards from taiwanese sources or so, I doubt there
will ever be a chance to have some microcode modification to recognize this.

You always have a chance to see what a good design the AS/400 is and was.

HTH, Philipp Rusch


Mark Phippard schrieb:

> In our search for a used Ethernet card for our Model 150, a sales person at
> a company wants to just sell us a standard SMC 10/100 PCI Adapter and
> claims that it will work fine in an AS/400.  I think he mentioned something
> about also needing to sell us some TCP/IP software for $75 (I can't imagine
> what that is).
>
> We already have several Intel Pro 100 cards around, and he claims they will
> work also.
>
> Is this true?  I tend to doubt it.  I know that it takes PCI cards, but it
> seems like IBM always loads some code on the cards that is required.  If we
> could just stick an Intel card in that would be great.
>
> Any help would be appreciated.
>
> Mark
>
> PS - I am just relaying this, I am not the one talking to these people.
>
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