Nekochan Net

Well...With the Datasheets for the different TLB entries and a socket header/base pair from here

http://www.bgaadapters.com/bga2301.htm

specificially

http://www.bgaadapters.com/images/BGAH-304-2301.PDF

and

http://www.bgaadapters.com/images/BGA-304-2301.PDF

AND someone that could make the necessary changes to the PROM, safest would be to use the one of the redundant CPU's that are still in the PROM it's all do-able

Even Joe said he'd use one of the sockets for the experiment as it meant that you could get the RM7000c @600Mhz running to eliminate that one variable, then switch in the faster chip with the modified PROM. Part of the reason I think he gave up on the faster PMC-Sierra chips was the reliability of the CPU rework and the time/cost if it didn't work. At least with a socket setup you'd have a known working re-worked CPU module to begin with, then nail down the PROM changes to get it to boot.

I remember when he was in touch with PMC-Sierra, they said all the PROM needed was a couple of lines changed for the 900MHz chips. Apparently the only difference between the RM5200 & RM7000(A, B, C), and the RM7900 is the TLB entries, they are pin compatible otherwise.

My (possibly incorrect?) recollection of events was that PMC-Sierra originally claimed the chip was 100% software and pin compatible (just like the RM7000/600 is). So Joe created a test module, and it didn't work. He then said it was a software incompatibilty, and there was something in the PROM that needed to be changed to get it to boot, and that he knew the values needed (due to having access to the datasheet). I expect you would need it to definitively find out things like the PRid values, TLB entries, and to confirm things like cache instruction encodings and CP0 hazards are identical to the existing RM7000/350 (which would be the most obvious candidate for modification). And most importantly, MIPS chips often have model or even revision specific errata that might need workarounds.

I guess things would be much easier if there only were a socket for BGA305 CPU available,
which would allow to swap the processor without the heavy soldering ... is there eventually?

I´ll gladly donate some CPU modules that didn´t make it after soldering on a RM7000@600.

Walther

_________________
Valueing life is not weakness; disregarding it is not strength. -Mirage-

Check my earlier post, they are available here

http://www.bgaadapters.com/bga2301.htm

They've got sockets which are soldered to the board and another which is soldered to the chip

They're a press fit with pins from the header and CPU attached going into the socket on the board.

Not sure on the price though, but if you weigh up the cost of damaged CPU boards from failed swaps and the ability to go to the RM7900 if the PROM issues can be solved it might be worth it

Nekochan n00b greetings from a longtime Irix-o-phile (Indigo2 SI for the win), and recent (yesterday) O2 owner!

jan-jaap, or anyone else who knows: can you please recommend to me a place in the NL/BE/DE/FR area that is able to perform the necessary chip-swap work on an RM5200 board? I've found a PN# 030-1493-001 for OK-ish money online, but I want to be able to line everything up with a certain degree of surety first, rather than blowing money and hoping.

Oh and incidentally, my girlfriend is from Wijchen

_________________
8/E 8/M

'edefault' (see a few posts up) is the guy who has the parts to do the conversions on suitable RM5200 modules. He is based in Germany. Perhaps send him a PM.

We are currently trying to accumulate enough modules for a batch.

Ian.

Mine isn't

But I guess it means you're in the neighborhood often -- If you'd like to see a bit of SGI history, just PM me.

_________________
Now this is a deep dark secret, so everybody keep it quiet
It turns out that when reset, the WD33C93 defaults to a SCSI ID of 0, and it was simpler to leave it that way... -- Dave Olson, in comp.sys.sgi
Currently in commercial service: (2x)
In the museum: almost every MIPS/IRIX system.
Wanted: GM1 board for Professional Series GT graphics (030-0076-003, 030-0076-004)

Spoken to edefault. You can count my module in...when I get it! For lack of a European supplier of RM5200 boards I'm having to order mine from California, which will mean it's at least a week before I have it.

_________________
8/E 8/M

Have received my 600MHz module and it's happily running with a fresh install of 6.5.30! Fantastic It booted once or twice on the 6.5.29 install I was running with my 180MHz R5k, but otherwise would fairly consistently hang during boot with the 600MHz module, and very consistently would boot with the 180MHz one. I mention this in case anyone else has a similar issue-- luckily as I have piles of SCA80 drives sitting around, reinstalling was pretty painless.

_________________
8/E 8/M

Ha ... congrats! Btw., I tested the modules with a 6.5.28 IRIX Installation running MySQL5, Apache2, Joomla!, OpenOffice, Blender ...
Since I had 3 modules out of 12 from the last batch that din´t boot properly into IRIX I´m curious if these would run with a fresh install.
Unfortunately, I don´t have a couple of system disks at hand - I use my intranet server as guinea pig for newly converted 600MHz modules.

Some recipients of converted modules reported difficulties I hadn´t that vanished after exchanging RAM modules in the past.
Always a good idea to check for RAM that´s fast enough.

Cheers

Walther

_________________
Valueing life is not weakness; disregarding it is not strength. -Mirage-

Any data on RAM module brands which are known to have problems with the 600s?

Ian.

BUMP!

I am fairly certain I had a converted R7000 O2 amongst the "pile" of SGI I still had to sort, that was reported to stop working after about a year of use. Since a friend of mine has access to flow and reflow equipment, I tried to find the O2 in question and get the board out for reflow. I went through several rooms, gathered all the O2s I could find, tried booting them and one with a Rev. B CPU board didn't boot. I took that CPU board to the reflow guy and we there tried to pry the cooler off. Well, it came off, taking part of the CPU with it. I'm not certain it was in fact an RM7000/600, but it's broken now so I might as well put one on.

I'd like to get my hands on an RM7000/600 CPU and a PROM so I can get this board fixed and make certain it'll run properly. Does anyone happen to have spare CPUs or PROMs available, or access to "affordable" parts? I found a supplier for the CPU, but a single one will cost over $150 including shipping and I'll probably get import duties and fares over that. That will make the price a bit steep for "just an experiment" so I'm hoping for a friendlier alternative.

The price for this type of CPU never came down over time. 150$ is not a fortune; i would say you are lucky to find a supplier at all. I can remember that i have spent more than twice as much back in time when i got the parts from chicago joe. The system still works pretty well today.

If you don´t want to spend this much money you might still got to ebay and get a standard 300MHz R7000 or any R10000 for small money. That should be sufficient to revive the dead machine.

I have 4 or 5 O2s on the shelf. Since it'd be a "fun" project, the objective is to do it on the cheap. Spending this much money on an SGI would probably not be the most productive way to throw money at my SGI collection. I can think of other things for other machines that would be much nicer to have than spending over $150 on getting an O2 to run at 600MHz.