Metamorphosis

by Mad Dog

emptyslots

This has been my most agressive modifcation to date, as it has included motherboard soldering.

Some time ago I purchased a "kit" on Ebay from www.upgradestuff.com (good deal for $49 + shipping) for the following items:

- J700 motherboard
- floppy
- Apollo card (ethernet, printer ports)
- 200 MHz 604e card

All one needed was a case, video card, powersupply, HD, and cables to get it going.

The powersupply I bought from www.smalldog.com, as it is not a standard ATX supply.

The case I bought from a local store (ATX style; Enlight 3270 or something like that).

Cables, video card, and HD I scrounged from what I had.

When I read the specs on the J700, I saw that it had 4 PCI slots, with 2 slots just soldered over (slots E and F).  The J700 was the lower cost cousin of the 6 slot S900 motherboard.  After investigation I found that:

- The J700 seemed to have all the PCI controller chips that the S900 had
- The ROMS are the same for the J700 and S900
- One person (M. Isobe, famous hardware hacker) has claimed to have done this
- The only differences between the J700 and S900 seemed to be the missing 2 PCI slots and the missing second CPU slot

This lead me to believe that you could add the 2 missing PCI slots. Lets get Nasty!

Equipment:
You will need the following items:

- a 23 Watt (or so) soldering iron with a fine tip.  I dont think a 15 Watt iron has enough oooommph to desolder.
- Two PCI slot edge connectors. I bought mine from www.digikey.com, part #145154-4 or 145154-8 (some confusion here).
- fine, narrow desoldering braid (copper).  I bought some at Radio Shack, part #64-2090B.
- some solder, preferably lead-free silver containing solder/  I bought some at Radio Shack, catalog #64-025.
- A can of light flux(resin) remover.
- A clean, well-lit place to do your work, preferably over a non-flammable surface.

Step1
Make sure the equipment works before you have a chance to screw it up.

Step 2
Flip the motherboard upsidedown, as there is less congestion on the backside. Have the motherboard resting on some bubblewrap or something soft, in order not to damage any of the components (be careful not to touch the hot iron to this).

Step 3
Using the solder wick and the iron, gently wick up the solder from each hole in each soldered over PCI slot (120 holes per PCI slot). The trick here is not to hold the iron too long on any one spot and overheat the board. For me and my iron, if I put the iron and wick on a soldered over hole just right, it takes about a 3-count to wick up all the solder. Be very careful not to knock off any SMT resistors or other parts. Also be careful not to scratch any traces or lift any of the green leads from the motherboard.
Careful, steady work should take a couple of hours. Remember not to overheat the board so I suggest doing a hole one one side of the slot, then another hole on the opposite side.
You will likely notice that after removing solder, a brown-black residue is left over near the holes.  This is normal, and is solder resin.  This resin can be removed with the flux-remover spray (after the board has cooled).

After removing the solder from one of the PCI slots (sorry its a little dark):

Step 4
Using the solder wick and the iron, gently wick up the solder from each hole in each soldered over PCI slot (120 holes per PCI slot). The trick here is not to hold the iron too long on any one spot and overheat the board. For me and my iron, if I put the iron and wick on a soldered over hole just right, it takes about a 3-count to wick up all the solder. Be very careful not to knock off any SMT resistors or other parts. Also be careful not to scratch any traces or lift any of the green leads from the motherboard.
Careful, steady work should take a couple of hours. Remember not to overheat the board so I suggest doing a hole one one side of the slot, then another hole on the opposite side.
You will likely notice that after removing solder, a brown-black residue is left over near the holes.  This is normal, and is solder resin.  This resin can be removed with the flux-remover spray (after the board has cooled).

After removing the solder from one of the PCI slots (sorry its a little dark):

oneslotB

I would suggest taking a break after doing one slot, letting the board cool, and using the flux removal spray to clean the resin off.

After removing the solder and resin from the second slot:

twoslotB

After allowing the flux remover to evaporate away, I took the board into my workshop, hooked it up, and:

boots2

It boots ! Wahoo !  Looks like I havn't screwed up yet, so this still may work !
 

OK, I just got 2 sets of edge connectors from www.digikey.com (part # 145154-4 and 145154-8, these are AMP parts if it matters). It turns out these 2 parts differ only in the length of the tails on the bottom of the connector, so either should work.

One pic of a connector:

Connector

M. Isobe (see: bbs.xlr8yourmac.com/ubb/Forum11/HTML/000143.html) thought I should use AMP part #11299-4, but I could never find anyone who would sell me this part (Digikey didnt stock them).  As far as I can tell Isobe's parts or my parts should work; all the documentation seems to indicate all of them should work.

Anyway, the part looks like a duck, reads like a duck , so it must be a duck ! (I hope)

So Let's get Nasty !

Taking one of the connectors (I decided to use the -8 part first), I carefully put it into the Slot E holes which I desoldered earlier.  I made sure all of the pins were through the holes and sticking out the other end; if you make a mistake here, you will most likely have to clip the partially soldered-on connecter off and de-solder the pins out (UGLY !).  One the pins are through, make sure the connector body is flush with the motherboard; you dont want a PCI socket soldered on an angle which would make using it very difficult.  I should also mention the connector only fits in one direction, so it is impossible to put it on backwards (although I had nightmares of doing just that).

Solder the 4 corner pins on first and check to make sure the connector is still flush with the motherboard.  If everything still looks ok, solder each pin in, careful not to use too much solder, but enough to make a good connection. Try not to heat any one part of the motherboard too much for too long, so I suggest alternating different parts of the socket.

I soldered in Slot E first in case I made a mistake.  I then took the board back to my laboratory, hooked it up, but in not using the new slot. It booted and I then shut down and placed the video card in Slot E:

5_slot

I hit the power button...... and... IT WORKED !  It booted !

5_boots

Slot E functions with a video card in it ! Tattletech sees the J700 (mutant, now) as a 9500/9600, and reports the card to be in Slot C (for some reason if I put the card in slot D (originally present) E, or F (see below) TattleTech sees the card as being in  Slot C. Is this normal ?

Ok, this was the big test, since the video card worked in Slot E, I have few doubts we cant do Slot F.  So, a-solderin' we go !

Using the same procedure as before, I soldered Slot F on to give:

6_slot

I connected it up with the video card in Slot F... and..... It WORKED !:

6_boots

The video card works in Slot F.  I think this pretty much concludes that all the PCI curcuitry from the S900 is there on the motherboard.

After disconnecting the board, I used some flux remover to clean up the resin.  it pays to be tidy !

I need to do some sort of test to make sure the slots are all 100% perfect.  While the video card works I wonder if there is a better way to stress the slots, just to be sure.

Oh, I almost forgot, while soldering, I added a jumper to J38 which is the manual dsiable jumper for the L2 cache, which should allow for better overclocking results. Evidently some J700/S900 boards have the jumper while some don't.

WAHOO !

J700 motherboard in a ATX case.

OK, half our work is done.  Now that we have sucessfully modified the motherboard we need to find a home for it.  I bought an Enlight 3723 case, as it has good reviews on the PC sites.  It cost me about $80 at a local shop, but that includes the ATX powersupply that we dont need for this project.

The J700 motherboard has mounting holes that fit a ATX case, so that is not problem.  When putting the board on the mounting plate, make sure that the motherboard is flexed as little as possible.

The first hitch I ran into was finding that the motherboard is so wide, part of it bumps into the lower 5.25" bay !  Other cases may not have this problem as the Enlight case has extra bays.  Im sure a full tower case would not pose this problem.

However, You can remove part of the bay using some tin snips and a dremel tool.

After removing part of the bay:

Case3

Not terribly pretty, but no one will see it.  After doing this , it may not be possible to use the lower bay for a hard drive.  Smaller drives may fit or you could use the bay for cooling.  A cooling and temperature gauge plate:
http://www.jameco.com/cgi-bin/ncommerce3/ProductDisplay?prmenbr=91&prrfnbr=4070&cgrfnbr=501&ctgys=
may be a good way to utilize the space.

After fitting the motherboard into the hacked case, the next problem shows itself:

Case1

The ports on the backplane dont match up to an ATX form, so either you will have to leave it open (yuck !), or manufacture a cover plate yourself.  At the moment, I am trying to see if I can make a cover plate from plexiglass.

Taking another look inside the case:

inside

We can see that the CPU card also needs some sort of support, just to be safe.  The CPU card sticks out a bit to the front, so I dont think it is possible to use any of the 3.5" bays, other than the floppy bay.

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westieg3's picture

wanna ask. is there a locatio

wanna ask. is there a location to solder in another processor slot right next to the existing one? i'm wondering what that is for if not.

An Answer and Supplemental Information

You ask if it is normal for cards in slots E and F to be reported as in Slot C. Yes, on the S900 and J700 that is normal. Umax took the Apple hardware for a 3-slot machine, A, B, C, and stole the last slot, C. Then, in Cs place, they put a PCI-PCI Bridge chip which converts 1 PCI slot into four PCI slots. Any card in slots C - F are behind the PCI-PCI Bridge and so appear to the Mac to be in slot C.

Also, on Macs of this generation, each PCI slot has it's own dedicated interrupt wire. However, this scheme with the PCI-PCI Bridge means that slots C - F are all sharing slot C's interrupt line.

The ATX power supply can be converted to a Umax power supply, which is useful because Small Dog no longer has the Umax supplies. I have an article about the conversion here: http://www.io.com/~trag/Umax_ATX_PS_rev_2.sea.hqx Tom, if you want to host a copy here you are welcome to do so.

There is also some useful information at the very end of that article about getting the rear speaker port working, if you don't have the Venus sound board for the front speaker port.

Finally, I have a printable template... Well farkle. I was about to write that I had a printable template for backplane ports cover, but that's for the PowerTower Pro http://www.io.com/~trag/PTP_template. I never did one for the S900 because I found an outfit in California which was selling the covers. They're typically called an I/O Gasket, or an EMI Shield. The place that used to have them was calpc.com and htey called them a Storm Surge EMI Shield, I think. That was about six years ago. Might be worth a call to see if they still have any laying around. I think they charged me $5 each.

madmax_2069's picture

Wow what a nice Mod. and what

Wow what a nice Mod. and what a good write up on how you did it. and good job on what you have done and works great so far.

But do you know how many Mac's have the ghost ports AKA places for PCI slots but there is none there. or have a place on the mobo for a PCI cpu but the slot isnt there

i know on my Beige G3 AIO there is a place on the mobo for a 604e CPU but the slot was not installed. People with a Beige G3 can look for themselfs right next to the zif socket.

orignaly the Beige G3 was supost to have the 604e CPU insted of the G3 CPU. but apple found out the G3 was a way more powerful CPU so the opt to use that insted of the 604e.

i would love to see a list of Mac's that have these Ghost Ports. and i would love to see what ones have the ability to use them once installed.

EDIT: Wow i didnt relize the date of the OP someone must have been doing some grave digging in there spare time. wow this post is old. but very intresting none the less