View Full Version : PDS Video Card Adapter

05-23-2003, 09:04 PM
I have a PowerMac 7100 into which I'll put my 6115's Sonnet Crescendo G3 accelerator.

I'd like to make my own adapter to connect the 7100's PDS video card to the Crescendo.
Fabricating the video card holder itself would seem to be no problem (though I could be wrong).
And I was thinking I could perhaps mount the video card in a way that doesn't sacrifice the
use of the middle Nubus slot - the Nubus slot being the card holder "foundation" as Sonnet and I think Newer Tech does.
This would involve installing mounts and cutting another hole in some available section of the 7100 box.

Obtaining the right PDS connectors and the associated cable-ribbon is the for me challenge now.

I think the correct PDS connector I need is designated "EuroDin 120 pin".
I'm in a convoluted search for connector parts...maybe this is a good start?:

Card Edge Board-to-Board ... Product Type Search

Further searching this site's various links leads to a lot of model numbers, no images.
The PDS slot on the 7100 has "AMP" printed on it.

Has anyone ever obtained the right parts and fabricated his/her own adapter similiar to what I am trying to figure out?


05-24-2003, 06:39 AM
Whew, Sonnet still wants $100 for the Crescendo AV/HPV Card Video Adapter Kit (for 7100/8100) and that wouldn't solve your desire to retain the middle NuBus slot. Yes Newer used the same idea of stabilizing the AV/HPV card in the middle NuBus slot.

I have never seen the Crescendo version but the Newer version had an extremely heavy and pre-bent from the factory connecting cable. You were warned not to fool with the cable bending which of course caused some folks to re-bend the cable in order to regain the NuBus slot with disasterous results. That cable, though heavy, is apparently fragile wiring inside. It has been awhile, but if I recall correctly the cable length is also somehow tuned by the electronics on the G3 board, but I could be totally wrong about that.

I do remember that when both Sonnet and Newer started offering the optional Video Card Adapter Kits, both had a lot of trouble with the fragility of the cable, either DOA or user installation. Sonnet stopped offering the kit for awhile and offered a NuBus video card instead, the Sonata Pro 24 NuBus Video Card (by Village Tronic?), a rebadged MP340.

I have no idea about the parts. I do know that Guru Moderator Trag knows or could figure out the info you need. I have not seen him on the forums lately. But I would be very careful about cable bending. k

05-24-2003, 08:04 AM
Thanks for the info, kaye.

A custom ribbon deal sounds like it may be a tricky and sensitive
issue....gawd, I hope not....if not then

I wonder if instead of a ribbon connection to the PDS-Video card, a
card-like "Y" PDS adapter could sit in the main PDS slot.
One slot for each...but not exactly a "pass thru" slot, http://macgurus.com/infopop/emoticons/icon_biggrin.gif
The video card would be inside the 7100 case so just run a longer db25 monitor cable to it.
....brother...now I'm really hallucinating.. http://macgurus.com/infopop/emoticons/icon_biggrin.gif

Hmmm...how about just raising the short Crescendo card higher via a PDS-slot
"extension" so the video card could still stick out, possibly above the
(hopefully not too tall) Nubus card near it ?

Check out this pic -- an example that raises an LC's ethernet card higher in order
to negotiate around a PPC upgrade card:
Here's the info about this LC's setup:

ahhh...if only things could be so simple.


05-24-2003, 10:10 AM

I've seen NuBus slot extenders but never a PDS slot extender before. I have to think that a PDS Y adapter would not work because both cards would be fighting for the slot. There has to be some kind of controller on the G3/G4 card to keep them working in sync.

However, I just remembered that at least one of the G3 cards I had, either the Newer or Sonnet card, where the cable connects to the card, is actually a PDS slot itself. I remember plugging in an HPV card into my G3 card and mechanically the HPV card plugged right in. The G3 card cable connector was such that the HPV card was at a right angle to the G3 card (an inverted L) and oriented towards the NuBus slots. However, the "new" PDS slot on the G3 was offset so that the HPV card either impinged on the backplane of the case or was towards the center of the case, can't remember which for sure.

But I think the problem was the HPV card hit the backplane. you may be able to deal with that if your Sonnet card has a PDS slot for connecting the cable. Perhaps a couple of those PDS slot extenders to raise the short Crescendo card and attached horizontal HPV/AV card enough so that you don't lose the NuBus slots under the HPV/AV card. k

05-24-2003, 07:40 PM

I think you're right about the video card's far edge hitting some part of the 7100's case when fitted into the accelerator card's pass-thru slot.
...even if the pass-thru slot was high enough above the NuBus slots.
I did a hand-held dry fit with a bare 7100 mobo sitting in the bare 7100 case.

I should just get the best available NuBus vid card for my needs and be done with it.
...tho I did rather like the idea of having a G3-accelerated 7100 with three NuBus slots available for non-vid card duties, but oh well.


05-25-2003, 09:23 AM
There are quite a few old NuBus video cards. One of the advantages of the HPV and AV cards is that there are no drivers and no software required, just the OS Monitors control panel. Another advantage of the HPV/AV cards is that they run most of the old games. The NuBus video cards, on the other hand, kind of went unsupported either just before or in some cases just after OS8.6, and some are less tolerant of old games. You could still use the Monitors CP to change resolution and color depth, but to turn on acceleration whether hardware or software required another control panel or extension that may or may not work beyond OS8.6. What OS are you running?

I participated in a small group of G3 accelerated NuBus owners who were looking for the fastest video card. We shared our results. The 4MB VRAM version HPV card was hard to beat but the Radius Thunder IV was the best (avoid the Thunder II), the MP340 second (MP320 slower), the 4MB HPV card third. Many were very poor. The NuBus bus speed of 10MHz is a very limiting factor compared to the PDS slot bus speed which varies with your machine, but roughly 30-40MHz.

The NuBus restriction relates not only to the CPU bus speed vs. NuBus bus speed ratio, but also to the NuBus controller chip, BART4. Later 8100's (8100/100 and 8100/110) have an improved NuBus controller chip, the BART21. However, those models are still stuck with the CPU bus speed vs. NuBus bus speed ratio problem. The ideal NuBus, therefore, is a WGS9150/120 and Power 120 which have the best CPU bus speed vs. NuBus bus speed ratio AND the BART21 NuBus controller chip.

Several differences between BART4 and BART21, but the highlight difference is that BART4 enables burst transactions for the bus as a whole, whereas BART21 enables burst transactions for specific slots and also handles burst read transactions by NuBus masters. The result is a faster NuBus, how much I don't know since all of my machines were BART21.

There are four models of the good Radius cards, the Thunder IV GX*1600, IV GX*1360, IV GX*1152, and Thunder/24 GT. The first three differ in how much VRAM is on the card and the first three have a removable piggyback DSP accelerator (4 DSP's) for Photoshop up to v3.0.5 I think. You must remove this piggyback card for G3/G4 machines and its extension, and the G3/G4 will accelerate Photoshop much more anyway. The Thunder/24 GT is exactly the same as the IV GX*1152 but without the piggyback card. This is what the cards look like http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2727558298&category=25449

I used the IV GX*1600 which, on a 21" monitor, would give me up to 1600x1200 at millions colors, the IV GX*1360 up to 1360x1024 at millions, the IV GX*1152 up to 1152x870 at millions. Hope this is not information overload. k

05-25-2003, 12:25 PM
Thanks for the info, kaye.
It helps explain the working differences with the hardware involved.

The OS I plan to run in the 7100 is 9.1 which is the same running in the 6115 right now.
The use that I want the 7100 to perform is an open issue,
but I wasn't gonna have it be an accelerated Photoshop workhorse or go beyond games with 256 colors.
I can scrape by with a G4/400 AGP/GeForce2 MX and gig of ram for the heavier stuff.
See, actually my original plan was to "play" with a G3-accelerated NuBus mac while my G4/400 was busy exporting or rendering.
The thing is, my current G3-accelerated NuBus mac is the 61xx which doesn't provide much expansion to play around with audio or video, hence the 7100.
I'll have to get a hold of a couple more 32 Mb ram sticks for the 7100 though.
My 6115 has two 64 Mb sticks in it.

With the 7100 and a 4 gig HDD I was thinking of playing around with Midi, vinyl rips (would like to find an Audiomedia II) and leech from Usenet.
Also I was thinking of having the 7100 do some 320 X 240 video work with a Sigma Designs card...tho I read the 7100/66 mobo/Nubus is flaky for video compared to the 7100/80/Nubus relationship.

Regarding a Nubus video card...I read lowendmac's Nubus video card advice about the Supermac Thunder 24 being compatible with OS 9.1:

Oh, I was also thinking of swapping out the 7100's CD-ROM with a 6x4x16 Yamaha burner...unless the heat would be an issue.


05-25-2003, 03:54 PM
The SuperMac series are the Thunder II series. They are 12" NuBus cards and don't fit in all machines. If the SuperMac will run OS9.1, then so will the Thunder IV series, 7" cards and significantly faster. k

05-25-2003, 07:41 PM
Ah cool.
OK, I'm reading about the IV cards here:

...says something about a possible glitch with virtual memory but
at the same time good compatibility with the G3 accelerators.

do you know anything first-hand about the Futura II SX video card?


05-25-2003, 10:07 PM
I had forgotten about the requirement for virtual memory to be off but my NuBus machines were always RAM maxed out so I never ran virtual memory anyway.

I know nothing about the Futura II SX video card. I remember Macworld ran a test of four video cards back in 1996 but could not remember what cards were tested besides the Thunder IV, so I looked and reviews that old are long gone. k

05-26-2003, 06:28 AM
OK, Thanks kaye,
You've been very helpful with your replies.

I now know more about a few Pros and Cons involved.


05-26-2003, 08:52 AM
Now I remember, you must disable virtual memory to use the piggyback PhotoEngine card for Photoshop. With a G3/G4, you can't use the piggyback card anyway. The Thunder IV card itself does not require virtual memory disabled. My memory comes back in small segments.

And yes, I have also read that the 7100/66 mobo/Nubus is flaky for video compared to the 7100/80/Nubus relationship tho I have never spoken with someone who actually had that problem. One thing I remember very well was helping someone with two maxed out 7100s, a 7100/66 and a 7100/80. He had two Newer G3s, I think one was a 220 and the other a 300. Regardless of which machine, the G3/300 would sometimes not cold boot but always reboot. We worked on everything until finally he put a voltmeter on a spare Molex power plug and discovered the G3/300 was drawing significantly more +5V DC during initial startup. If it dropped below +3.6V DC during that initial power draw, the machine would not bootup. The power supply on the 7100 is limited with a maxed out machine. k

05-26-2003, 10:08 PM
Hi kaye,
I have another question.

kaye said:
"The 4MB VRAM version HPV card was hard to beat but the Radius Thunder IV was the best
(avoid the Thunder II)"

What exactly is bad about using the Thunder II series with a G3-accelerated NuBus Mac?

I happened to read this user's quote:
"I am using my SuperMac (Radius) Thunder II GX - 1360 on Mac os 9.1,
on a PM 8100/110 with 144 MB RAM and a Newer Tech G3 upgrade."

Well, the main difference (compared to my situation) that I can see is that this user has a 8100/Newer Tech, not a 7100/Sonnet Crescendo.

Arrggh...In some cases, it's too bad there's nothing absolute about massed-produced computers
and their optional working components.
Sometimes the reality of YMWV (Your Milage Will Vary) leads to
impulses of recreational-brain-cell-killing consumer indulgences.


05-27-2003, 06:35 AM

I found a few old tests on the SuperMac Thunder II:



Thunder II uses slower VRAM (in its time I think it was called eWorld VRAM), the board electronics is slower, the software is less mature, and the 12" NuBus card length physically won't fit in some computers. Sometimes it is the length, sometimes it is something on the mobo that sticks up far enough to prevent fully seating the card in the NuBus slot. You might find that at least one of your NuBus slots will take the 12" length and nothing on the mobo will prevent seating the card.

Radius bought out SuperMac and later came out with the Radius Thunder IV NuBus series with faster VRAM and electronics, better software, 7" length. My guess is that either card will cost about the same at this point in time. k

05-27-2003, 07:47 AM
Whoa, amazing article find, kaye.

I suppose I could live with the rated performance....NuBus afterall.
A vid card 12 and a half inches long...
That's nearly pushing it even with a bare mobo....I'm holding a ruler in the case.

Hmmm...yeah, nice vid card prices 10 years ago....like buying a G4 today http://macgurus.com/infopop/emoticons/icon_biggrin.gif

Yes, I think I like the idea of a 7" Nubus video card.

Too bad I had to base another retro PPC on my available Crescendo.
Seems I would have been better off starting anew with a base PM 7500.
I'll just have to have patience, and maybe I'll get my moments of serendipity.

Thanks for all the info,