eMac 700 and BEOWULF Project

Posted by: netjosh_granada

eMac 700 and BEOWULF Project - 01/13/05 01:42 PM

Hello to everyone,

I'm new to this forum but not to other technical forums and I have a BIG question:

I have a bunch of eMac 700 Digital Modules (Down converter, Logic Board, aluminium drive tray, cables, etc...) from a series of CRT-dead eMacs, but I DON'T have the Analog Modules (power converter) that provides the digital module all the voltages needed for the computer to work.

I've been thinking on using ATX power supplies to make them work but I need advice from all you "Pro" around here, because I'm planning on using these in a "Beowulf-like" computer cluster system in the office, and I have everything prepared, excepting info on power connectors.

I know that the Logic Board's "Blind-Mate" connectors provides all the electric connections, and in macrumors.com forums I saw a post in which someone traced voltages on these "Blind-Mate" connectors, but it gave me no clue to do all the rerouting and rewiring to make the ATX power supplies work, mainly because it had different voltages in each pin wether the emac was on or off.

I see this project like some kind of BIG CHALLENGE, and it would be great to be able to use all the eMac Digital Modules on a Great Performing Processing Center (I'm planning on using it to render video and other calculation-intensive applications).

Any help would be appreciated,

Thanks.

Post edited by: netjosh_granada, at: 2005/01/13 21:44

Post edited by: netjosh_granada, at: 2005/01/13 21:46
Posted by: maestro

Re:eMac 700 and BEOWULF Project - 01/13/05 03:11 PM

Sweet, now if you could just put that cluster in one case, now that would be cool. As for you question-adapting any power supply isn't that hard, especially if you know the pin voltages on you eMac. All you need to do is find the schematics for any PC power supply and wire up a harness for it. As for the eMac connector, I don't know if you can match that. You could just desolder it and put on an atx connector. Good luck....oh, what program will you use your cluster for?

-Maestro
Posted by: whitlock

Re:eMac 700 and BEOWULF Project - 01/14/05 04:58 AM

If you can get ahold of an Apple Authorized Repair manual on the eMac, it will list all the voltages for everything so you can ATX-ize the power. Well, I was leaving the repair game when eMac's started to get produced, so I don't have the info. The iMac's did have all the voltage info on the CD that we had, so I would hope that the eMac would in its manual.

Try Google or bribe a tech, possibly find the post that it was mentioned in and work backwards from there. Anyways, if it's on a rumors site, always take it with a grain of salt.

BUT if you do have the voltages and which pins are what, find the pinout on an ATX power supply and work from there. Good luck!
Posted by: netjosh_granada

Re:eMac 700 and BEOWULF Project - 01/14/05 02:13 PM

Thanks for the ideas about getting an Apple Authorized Repair Manual. I didn't think this info would be available in this document.

The info about voltages I found in That rumour site came from the same person who achieved overclocking a 2nd generation eMac from 800 Mhz to 1,33 Ghz, so I think it comes from a person who know (more or less) what he does.

But again, thanks.

Refering to the configuration of my proyect, it is as follows (config for each eNode):

- 1st gen eMac, 700 Mhz G4 (FSB100), 256 Mb SDRAM, 10 Gb HD.
- Mac OS X 10.3.7 (for best performance & compatibility in Rendevouz).
- POOCH software (Parallel OperatiOn and Control Heuristic Aplication), from Daugher Research. This software allows to run mutithreaded aplications in different systems trough Rendevouz and 100 Mbps TCP/IP networks.

The HEAD/MASTER node is my "Workstation", configured as follows:

- iBook G4, 800 Mhz G4 (FSB133), 640 Mb DDR SDRAM, 60 Gb HD, Airport Express & Bluetooth.
- Mac OS X 10.3.7 and ALL the programs that can fit in a 60 Gb HD ;-)

One of the upgrades I plan on the nodes is to try tweaking FSB up to 133 and G4s up to 800-933 Mhz.

I'll keep you informed on the project status.

Thanks
Posted by: oojacoboo

Re:eMac 700 and BEOWULF Project - 01/15/05 03:59 AM

you should check the web links section of this site. There are some links to sites with archived repair manuals. Hope you find what you need. Do keep us posted.
Posted by: brokenmac

Re:eMac 700 and BEOWULF Project - 01/19/05 01:52 PM

I am hoping to do the same thing as netjosh_granada. I have a couple of emac logic boards but don't know the pinouts on the blindmate connector. I've seen the same info about the voltages and am a bit confused about the differing voltages depending on whether the emac is on or off. Somebody must know how to independently power an emac motherboard.
Posted by: maestro

Re:eMac 700 and BEOWULF Project - 01/19/05 05:14 PM

look at http://www.whoopis.com
-Maestro
Posted by: Nate

Re:eMac 700 and BEOWULF Project - 01/22/05 08:23 PM

whitlock wrote:
Quote:
If you can get ahold of an Apple Authorized Repair manual on the eMac, it will list all the voltages for everything so you can ATX-ize the power. Well, I was leaving the repair game when eMac's started to get produced, so I don't have the info. The iMac's did have all the voltage info on the CD that we had, so I would hope that the eMac would in its manual.

Try Google or bribe a tech, possibly find the post that it was mentioned in and work backwards from there. Anyways, if it's on a rumors site, always take it with a grain of salt.

BUT if you do have the voltages and which pins are what, find the pinout on an ATX power supply and work from there. Good luck!


Sorry to resurrect a dead thread, but I have the iMac service manual and can't seem to find this voltage info you speak of. Is it a separate file? Do you still have it?
Posted by: whitlock

Re:eMac 700 and BEOWULF Project - 01/22/05 08:34 PM

I don't have access to it anymore. The voltage info was on a sepperate file, if I remember. I can't remember if it was on the same Apple Service CD, or on a supplimental CD. It's been over a year now, and I cannot remember those details too well, but I do remember seeing them because I had to use a multimeter to test parts of the board all the time.
Posted by: maestro

Re:eMac 700 and BEOWULF Project - 01/22/05 09:55 PM

That is a kick ass project. I would stay away from clocking the bus though. You would need new ram and who knows if thay L Board will handle it without a voltage change. Really I think just up clocking the cpu to 867 could be cool, although you will need to figure out how to cool the cpus better.
-Maestro
Posted by: netjosh_granada

Re:eMac 700 and BEOWULF Project - 01/23/05 11:54 AM

It's me again, and I have some bad and "good" news for all.

I have been talking with a technician who works at an AppleCenter near (150 Miles away) my city (This is the great existence of Apple in southern Spain) and told me that the only document they have access to is the "Apple Service Source" document. As you all know this document is scarce in technical information apart of replacement parts installation.

Alternativelly, I tried searching in Apple's own Developers database ( http://developer.apple.com ) and found the complete Apple eMac Developer Note. The bad news is that there's a lot of info about the eMac (even USB and video out pinouts), but none about these "Blind-mate" connectors.

Now that I know that there's (in theory) no information available for the pinouts, I will do the following:

1) With the info available about the pinout voltages (see pic on the top and schematics down), I will start connecting each pin with its equivalent on the ATX PSU. The problem, as I see it is on pins 1-2, which I think are high current lines that go directly to the down converter board. I will talk with a friend of mine who knows a lot about electricity-current conversion to see what can be done here, as I don't want to fry the logic board when shut down. But before all, I'll see if the eMac starts with "just" +12 V attached to pins 1-2, because after all, drives will be fed directrly through the ATX PSU, not the down converter board.

Pinout considered to be:
08 07 06 05 04 03 02 01
16 15 14 13 12 11 10 09

Code:

Pins_______eMac ON______eMac OF
----------____----------_____----------
01___02___+20.3V______+12V
03___04___+12V________+12V
05___06___GND_________GND
07________+19V________+11.5V
08 ..12____GND_________GND
13________+0.3V_______+8V
14________+0.3V_______+0.3V
15________+5V_________+5V
16________GND________GND

1,2 and 3,4 Looks like high current main power
7 ???
13, 14 Control signals to/from down converter board
15 +5V TTL logic power

I hope to have Good news soon!!!

And another thing, does anyone knows how to reroute the main video signal to a, say, Serial Port Connector to be able to connect an external monitor??? THIS WOULD BE PERFECT FOR THE PROJECT.

Post edited by: netjosh_granada, at: 2005/01/23 19:56

Post edited by: netjosh_granada, at: 2005/01/23 20:07

Post edited by: netjosh_granada, at: 2005/01/24 03:24
Posted by: maestro

Re:eMac 700 and BEOWULF Project - 01/23/05 12:41 PM

As for the connector-a connector is a connector, they mean nothing. What I mean is if there is enough pins to use, you can switch wires to any connector.
-maestro
Posted by: netjosh_granada

Re:eMac 700 and BEOWULF Project - 01/23/05 07:22 PM

Sorry for my "english", but what I was meant to say is that it would be great to trace the internal monitor connector pins so we all could use a standart monitor and not depend on video mirroring.

But again, thanks to all because it would be great that this thread could become a great guide for everyone who would like to make an "eMac Mod".

I'll post any news that would appear in the near future...
Posted by: oojacoboo

Re:eMac 700 and BEOWULF Project - 01/23/05 07:34 PM

as for the voltage testing, use a multimeter before ruining your board.
Posted by: netjosh_granada

Re:eMac 700 and BEOWULF Project - 01/25/05 02:28 PM

GREAT NEWS!!!

Today while surfing the net I have found a web page (http://www.ct-scan.com/iMacATX/) where it is performed an IMAC ATX conversion.

What is revolutionary here is that it is performed without any aftermarket solution (see Marathon Computer) and because I've found a way to power ANY eMac motherboard WITHOUT the Analog Module.

This new idea is the following:

[ul]Before finding this web page, I thought that the eMac motherboard SHOULD be powered through the "Blind-Mate" connectors available in the logic board, and so the down converter board should make it's work of providing the necesary current to each part of the logic board (including both drives power headers). This had lead me to the problem on HOW to measure voltages in both "Blind-Mate" connectors (only one in 2nd and 3rd generation eMacs).[/ul]

[ul]NOW, the idea is to power the logic board directly through the Down Converter Board's connector, which is the path followed by the author of this web page.[/ul]

Now this is the "not so bad" news that I have for this project:

[ul]The IMAC down converter board has 24 pins, all ordered and compared to its ATX counterpart in the diagram above, BUT (and this is a BIG BUT), the EMAC down converter board has 20 pins, and this is where I have problems when assigning each pin with its ATX counterpart.[/ul]

Now, I'm BEGGING anyone who could have access to an eMac (better if is a 1st generation one), to see and measure each pin voltage in the Down Converter Board connector, because this is the only thing that stops me from using a wonderfull eMac system.

Please, this help would be appreciated and would help me in achieving my next Project Goal, which is the rerouting of the internal video to an external monitor (something not too difficult given the great instructions found in this web page http://www.ct-scan.com/iMacATX/).

Thank you all in advance...

Post edited by: netjosh_granada, at: 2005/01/25 22:31

Post edited by: netjosh_granada, at: 2005/01/25 22:37
Posted by: netjosh_granada

Re:eMac 700 and BEOWULF Project - 01/25/05 02:33 PM

This is the iMac diagram to make the ATX conversion...

and how to make the connections:

ATX Pins
3,5,7,13,15,16,17
iMac Pins
3,5,8,10,11,13,22

ATX Pins
1,2,11
iMac Pins
1,12,14,16,18

ATX Pins
4,6,19,20
iMac Pins
4,6,24

ATX Pins
10
iMac Pins
2,20,23

ATX Pins with NO CONECTION
8,12,18
iMac Pins with NO CONECTION
7,9,15,17,19,21

Post edited by: netjosh_granada, at: 2005/01/25 22:46
Posted by: netjosh_granada

Re:eMac 700 and BEOWULF Project - 01/25/05 02:36 PM

And this is where is located the Down converter Board conector in the logic board...
Posted by: oojacoboo

Re:eMac 700 and BEOWULF Project - 01/25/05 08:19 PM

wow, excellent information josh. I know you are planning a great mod guide. Can't wait! :P
Posted by: whitlock

Re:eMac 700 and BEOWULF Project - 01/25/05 11:27 PM

After this mod, netjosh will be claimed "King of the eMac's"!

Good work on pulling up all the voltages and showing a good pic of the down converter. Very important info to have, especially since it's archived on the site now.
Posted by: maestro

Re:eMac 700 and BEOWULF Project - 01/26/05 01:27 AM

Im stoked to see this turn out. Glad to see you are moving in the right direction.
-maestro
Posted by: netjosh_granada

Re:eMac 700 and BEOWULF Project - 01/26/05 08:12 PM

Thanks to all!!

But, please, I am now at a STOP with this project until someone can provide me the information related to the Down Converter Board pinout voltages.

I would even PAY (yes...) to the 1st person that gives me this information, always after seeing if the logic board powers up ( ;-) ).

Please, could anyone be the one???
Posted by: krusher117

Re:eMac 700 and BEOWULF Project - 01/27/05 01:34 AM

I would LOVE to be the one, but regrettably I am not. SOMEONE PLEASE HELP THIS MAN! :P HE IS SO CLOSE
Posted by: Philon

Re:eMac 700 and BEOWULF Project - 02/17/05 03:12 AM

well, well.

I now must see that like many others, I had the idea of turning an eMac with a faulty display into a cluster node.

Interesting.

What I had in mind is putting the eMac into a rackmount case, just like what Marathon Computer did with the iMacs. Okay, I don't think I can fit it into 1U, but 2U will probably work nicely. I also found some people saying, it's possible to overclock even the 700MHz, which realy would be great to get a bit more speed. Sadly, I didn't find any specific data.

Reading through this thread, attaching the ATX power supply is what holds us back from our evil ideas. I will have to make some phone calls, perhaps I can find out what we need, although I don't think this will be to easy.

For the questions about video, the video mirror port should work (with the VGA adapter) just fine for attaching an external monitor. I would prefer the SSH/Remote Desktop way, like on the xServes

best regards and keep up...
Posted by: netjosh_granada

Re:eMac 700 and BEOWULF Project - 02/17/05 06:34 AM

Hi again, I'm the one who started it all.

After such a long time without posting anything I'm here again to tell everyone that this project is not Dead.

I've been in contact with the guy who overclocked it's 2G eMac up to 1.3 Ghz (Lbodnar) and he is trying to do the same with his computer.

I'm already waiting for some info he will provide me to see if it is possible to do this mod.

But after such a long time, I think I'm closer to make it work...