Does G3 Upgraded PowerMac6100 Dream of NuBus Card?

By Kuratate0

First report created: Oct.18, 2002

Open to the public: Nov.12, 2002

Last updated: Nov.12, 2002

Did you feel same thing when you upgraded your PM6100 with G3 card?

After you upgraded PowerMac 6100 by Newer Technology's MAXpowr G3 PDS card or Sonnet Technologies' Crescendo/NuBus, Apple AV card and HPV card (a.k.a. VC card) are the only option to upgrade the original graphics capabilities.

However, if you own the PM6100 with NuBus adapter card and one of the nice NuBus video card or any other kind of NuBus card, you may feel really sad when you upgraded G3 card and lost your precious NuBus card capability.

I was one of these sad PM6100 owners for a while. But when I got extra PM6100 from my friend, I started thinking "Is it possible to recycle this NuBus adapter card with G3 upgraded PM6100?" This was the beginning of this story. (Also I changed the title like the famous Sci-Fi story.)

How can I regain the NuBus capability on G3 upgraded PM6100?

Both MAXpowr G3 PDS and Crescendo/NuBus have a PDS slot that you won't waste your AV card or HPV card even after you upgrade your PM6100. That means NuBus adapter card is physically attachable to those G3 upgrades if you remove a metal bracket and ignore the position and the direction of NuBus slot.

Important questions are:

  1. Does NuBus adapter card technically work with G3 upgrades?
  2. Is it possible to change the position and the direction of NuBus slot?

The first problem is crucial. If it won't work, all NuBus treasures will be useless unless we gave up to use G3. It will be a difficult choice "G3, or not G3 (NuBus card), that is the question..." Anyway here is my report.

Warning! The following content in this page is just a report of my various tests. Those tests may have a possibility to destroy or damage the logic board, G3 upgrade card, NuBus adapter card and NuBus cards. I'm not encouraging you to do the similar thing. Just showing my results. There is no guarantee that you can get same results even you follow my procedure in this page especially extending NuBus slot requires special skill of soldering. So, read at your own risk. Even if you try and fail, that's your decision, your choice. Don't blame or sue me.

Does NuBus adapter card technically work with G3 upgrades?

When I had only one PM6100, I hesitated to try this NuBus test. But fortunately my friend gave me his PM6100/60, then I'm ready to do it!

  1. Test G3 card: Newer's MAXpowr

    PowerMac6100/60, 70M RAM, MacOS 9.04 Japanese

    Newer technology, MAXpowr G3 PDS 240-266MHz (MXP6100/266,512k 2nd cache), driver: MAXpowr Extension and MAXpowr Control version 2.0.5

    Test result: It works! PM6100 status up without any problems and works fine!

  2. Test G3 card: Sonnet's Crescendo/NuBus G3 Fortissimo 500MHz

    PowerMac6100/60, 70M RAM, MacOS 9.04 Japanese

    Sonnet technologies, Crescendo/NuBus G3 500MHz (CFG3-500-1M), driver: Sonnet Processor Upgrade version 1.47

    Test result: Doesn't work. It is not stable: it shows bomb at the start up, freezes during startup, shows red 'X' at the Sonnet Processor Upgrade. It never boots properly.

  3. Test G3 card: Sonnet's Crescendo/NuBus G3 Fortissimo 400MHz

    PowerMac6100/60, 70M RAM, MacOS 9.04 Japanese

    Sonnet technologies, Crescendo/NuBus G3 400MHz (CFG3-400-1M), driver: Sonnet Processor Upgrade version 1.47

    Test result: Doesn't work. Same as above...

We cannot use recent faster G3 cards with NuBus adapter card, but at least MAXpowr may be the answer of my question.

Next step is a test with actual NuBus card. However, now I have to face to another problem.

Is it possible to change the position and the direction of NuBus slot?

Since I knew that MAXpowr G3 worked fine with NuBus adapter card, I feel much better to do this. After I put NuBus adapter card to MAXpowr, the NuBus slot face directly to the logic board. As a primary test, I made a simple cable to extend NuBus slot. This time, I used materials available in my electrical junk supplies. I had 32pin flat cables and 96pin connectors same as NuBus connector for other purpose, I used those to extend the slot. It requires a good soldering technique to make this cable: you have to solder three rows of 32 pins with a flat cable for both ends. Figure 1 shows the cable I made. I know it is not beautiful. But if it works fine, I will re-design it.

Nubus Extension cable

Figure 1: Hand made NuBus extension cable

NuBus card connection through the hand made cable... does it work?

I made the cable little bit longer because I was not sure how I could configure NuBus card in the future. But after I made it, I thought it might be too long to send a bus signal without special buffering... Anyway, don't worry too much, let's try!

The physical configuration at the NuBus adapter is fine. It looks very close to the heat sink of original PPC601 CPU, but no physical contact as you can see from Figure 2.

PPC601 Heat sink

Figure 2: Closer look of NuBus slot and attached extension cable.

Anyway, cabling is finished. Now time to turn on!

Amazing! I can use both MAXpowr G3 and NuBus video card! Now I feel really happy and I can test more NuBus cards! Table 1 shows a summary of NuBus cards I have tested.

Table 1: Test results of various NuBus cards.

Card Type Vendor, Product Name
Results Comments
Video card Radius
PrecisionColor Pro 24X
Fine No problem
Video card Radius
Thunder IV GX 1600
It works, but not perfect Its highest resolution 1600x1200 is not stable.
First couple of minutes was fine for 1600x1200 and then suddenly I get a gray desktop. Even I can see the menu bar and the mouse cursor moving, I lost all other visual icons, folders and control strip.
I tired without DSP board, but it behaved same as before at that resolution. Other lower resolutions are fine.
Video card Radius
Thunder GT 1152
Fine No problem
Video card RasterOps
PaintBoard Prism GT
Fine No problem
Video card Sonnet Tech.
Sonata Pro 24
Village Tronic Computer
Mac Picasso 340
Fine No problem: even 1600x1200 and 1920x1080 with thousand colors!
Ethernet Card Farallon
Fast Ether TX-10/100
NuBus card PN990a-TX
Fine System behaves little bit unstable than without this card.
Wide SCSI card ATTO
SiliconExpress IV
DOES NOT WORK! I really wanted to use this card but I could not see happy Mac...
All I can see is initial gray screen from onboard video output...

I really thank to the engineers of 'former' Newer technology. You guys did good job, made the excellent product!

I hope the 'new' Newer technology will do good job too and good business!

New problems....

Now I know that I can use MAXpowr G3, NuBus adapter card and some NuBus card. However, there are new problems which I didn't mention before. The NuBus adapter card is too long! Even we had a trouble with HPV card that contacts internal HDD. But this one is little bit longer than HPV card.

Figure 6 is a picture around the NuBus adapter card with 2.5inch HDD. You can see the problem clearly. I haven't cut the rear part, then it is still sticking out.

Around the NuBus adapter card

Figure 6: Closer look around the NuBus adapter card.

Now new problems are not so difficult to solve. But there is one simple question: does NuBus card fit in the original case? I believe most PM6100 user love the compactness of the case. So do I. That means every thing must be in the original case!

Does NuBus card fit in the original PM6100 case?

It is possible if I choose smaller cards and remove a plastic pole that supports a load from the top cover, I could configure NuBus card many way though I cannot put heavy display on the top of PM6100 any more. For the video cards, I made a special DB15 video cable which is able to extend video output to the original rear slot window.

Important thing is electrical insulation: if I put the NuBus card inside of the case, it may contacts to the internal SCSI cable, edge of SIMM module and the internal shielding metal plates, etc. Also when I close the top cover, the metal plate attached to the cover may contact with the NuBus card, I must be careful about the insulation.

If I gave up internal CD-ROM drive, I may have more choice for the NuBus card. But I definitely need CD-ROM drive...


Now I regained the original NuBus capability for G3 upgraded PM6100 and I'm quite happy about it. But once I regained one function, I want to do more, upgrade more. The next step is "Can I get more NuBus slots?" I'm not sure... I need more time and information to get the answer....

According to the AppleCare Archive Article 2194, pin 26 and pin 27 in row A and C corresponds ID0 to ID3, geographical address which is hard-coded to slot. If I know the exact meaning of this 'hard-coded', it may possible to obtain more slots (at least one more for the internal case).

Additional test...

Nov.9, 2002

After I tested NuBus adapter with previous condition, I tested following Newer's G3 card and PM6100/66.

Now, I am a happy PowerMac 6100 owner again!

I'm extremly happy with my G3-PowerMac6100 which has a big screen like this!

Current Desktop with NuBus card