IBM RS-64 A35 Apache identification

[isa-d]

The IBM RS-64 CPU A35 Apache is one of those difficult-to-identify IBM processors, as well as the Power 2SC, and even though I had bought another one here in the forum I preferred to buy a entire CPU card and then compare them.
My surprise is that they are not at all the same and so who was wrong? below I will try to show that the right one is mine but every comment, suggestion or correction is more than welcome.
I purchased this on Ebay
https://www.ebay.com/itm/283249423058?
whose part number 87G0736 always points to the description "Processor card for 6xx series", here you can see, https: //en.wikipedia.org/wiki/IBM_System_i, that the AS/400 6xx has as its processor the RS-64 Apache.
But the first impression when I saw the board was that I was wrong and bought a RAM board.
Instead after some research I found on this page, http://www.secomp-intl.com/parts/catalog493.html, the complete code that in this case is IBM 9406 (FC2129) and from this page to a document official IBM, http://ps-2.kev009.com/as400/manuals/170_250_6xx_7xx_Sxx_System_Installation_and_Upgrade.pdf.






As you can see it is identical to my board and it is indicated that there is 1 processor, further down in the document it is also clearly written that it is a "Processor board"



So I would say without a doubt that the chip that is under the big heatsink is the RS-64 Apache A35 CPU, and then publish the photo.



It does not resemble its successors RS-64 II / III or IV but its predecessor A10 Cobra of which it has the same dimensions.
I hope it can help others and if I've made mistakes let me know, thanks.

[aberco]

I'll post photos of RS64 boards and earlier series that I have. I don't think that what you have is RS64, it is likely something earlier. The only way to be sure would be to pop the aluminum lid and compare die sizes.

[isa-d]

If earlier it must be an A10 Cobra and information on Wikipedia about AS/400 model are incorrect
but I finding this interesting book
https://books.google.it/books?id=ypJmzqt7JdUC&pg=PA18&lpg=PA18&dq=as/400+rs64&source=bl&ots=PqxFfVZKTa&sig=ACfU3U2CwiK1TMFC6FPe8XBGTtqpqDs9fA&hl=it&sa=X&ved=2ahUKEwiEjZKW3PXgAhWKa1AKHWDkDt0Q6AEwB3oECAIQAQ#v=onepage&q=as%2F400%20rs64&f=false
he write Cobra has a L2 cache off die on a separate chip, this match with my Cobra card because has two chips (CPU+Cache)
but on this card there is only one chip and must be the processor, I add also a picture of modell 600 (the same of my card) to avoid any doubt is the processor card

[aberco]

Check it out here:
http://www.cpu-world.com/forum/viewtopic.php?t=27454&highlight=apache

Unfortunately I don't have the photos of the boards as I am traveling.
The large RS64 chip (01L3123) comes from a 4 way CPU board with external L2 cache, running at 125MHz. The smaller one (01L3125) came from a 1 way planar board (see attached photo below).

I have several boards like yours where I have recovered the 2 Cobra chips, they have 72pin SIMMs and no L2 cache. Also they should be clocked at much lower frequencies (50-60MHz).

[aberco]

Is there date codes on the chips that are on your card? I know that IBM does not print date code on their chips, but there are other small logic chips that may have a date code.

Ultimately you could have found yet another packaging of A35...

[aberco]

So this is the board from 9401-150, which is the lowest-end of the same generation 6xx. CPU seems similar (based on the heatsink), and I think you're right, this is yet another package for the original RS64. You have the low-end version. These are mid-1997 releases when the RS64 was introduced, and these are probably not running at the full 125MHz.

[isa-d]

May be,

[aberco]

I have received this module, a 9406 AS/400 Server model 50S, 2121 processor module. It was advertised as a single CPU module so chances are that it is the chip in the middle, and there's L2 cache.
Date code on the chips is early 1995.
Chips are:
26H4553 (CPU?)
26H4501 (L2 tag?)
26H3566 (Clock)