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PM8100: all three NuBus slots free HPV install?

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Subject came up when I mentioned the full three slots free installation of a 2/4 HPV card on the floor of my Radius 81/110 Big Metal Can


@jeremywork asked if the same might be done in his PowerMac 8100  .  .  .  we'll see!





Now you've gotten me curious! Is that the same case as the 840AV with a fourth "NuBus" slot panel for the PDS VidCard in place of the "AV panel? of the 840? If such is the case, we've got a good starting place. :approve:




Which G3 kit are you using, looks like the Sonnet setup from here? If so you may or may not have a tad less room than the NewerTech setup, but I've got a Sonnet Kit stored away somewhere as well.


Case modifications are required, rough outline of process:


  1 -  Disassemble case sections.

  2 -  Remove RFI shielding on the floor of the case. (figuring we'll need to bend the retaining teeth up to get it off the pins)

  4 -  Figure measurement from edge of router base to back, front and center of slot to be cut in case bottom

__________ add 1 1/2" to each measurement for screwing 1x2" guides for router base on top of template (from bottom)

__________ allow for another 3 1/2" on outboard side for clamps, allows use a piece of 1x4" as a jig for mounting 1x2" router guide on outboard side

  5 -  Place RFI shielding on top of a piece of 3/8" plywood at the offsets figured above.

  4 -  Mark centers of back six holes to be drilled in template/router jig for centering it up with router base offsets front back and outboard side

__________ and mark anything else that might need to be removed to prevent router jig from sitting flat on the baseplate section

  5 -  Drill six holes for registration of jig and drill out or cut away anything else that might be in the way.

  6 -  Clamp the three guides to jig and use screws from bottom side to hold them in place

  7 -  Clamp jig onto sacrificial material or use spacers to protect worktop

  8 -  Use router to cut away section of template covering slot to be cut in bottom of case using a bit wider than final PCB+ thickness of slot in case bottom.

  9 -  Clamp jig to base unit and set depth of router bit so it removes about half the thickness of the case bottom away

__________ reassemble case (less the RFI plate) to test for fitment

10 - Remove backplane plate from HPV card and have at it! [:D]


The Slot will have been set up to hold the card parallel to the MoBo over the NuBus cards at a height matched to cable adapter height. WAG is that the HPV Card/Cable extension assembly fit without going through the bottom of the case. The arrow PCB+ slot will hold it in place vertically. Cable may or may not be pushing that side of card up too high, dunno, may need hold downs attached to PSU support shelf? No biggie there if so.


Is the 8100 board significantly better than the 7100 board if at all different? Can I use my 7100 board, same form factor or at least the slot section matches?

Edited by Trash80toHP_Mini

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I'll try to take some side-by-sides of the 8100 and 840av for comparison. I have many tools available, but having a hard time picturing all of your steps visually. My PDS cable kit is a Sonnet unit, and I suppose some vertical space could be reclaimed with a shorter PDS slot soldered on the ribbon, but that sounds far more tedious than cutting some case plastic away :)


Pics to follow soon...


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1 hour ago, jeremywork said:

I'll try to take some side-by-sides of the 8100 and 840av for comparison.

Just measurements from the bottom of the PSU support shelf to the top of the RFI shielding of both cases will do. Can't imagine it's not the same  .  .  .  then again  .  .  .  Apple. ::)



I have many tools available, but having a hard time picturing all of your steps visually.

Cool, that means I won't have to try to describe them verbally. That's not something I do well or easily, typical shortcoming of visual thinkers.



.  .  .   but that sounds far more tedious than cutting some case plastic away :)

Modify that adapter? Just NO! I'll try to find my Sonnet Kit so we're looking at the same thing.


Offhand, does anyone know if a 7100 board fit the 840AV case? Thinking it's a different form factor, but wondering if its slots will line up well enough for rough trials?




edit: cases are the same, both based on the Quadra 800, per LEM anyway.


Edited by Trash80toHP_Mini

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Every time I touch this freakin' 840av case more plastic breaks off and parts fall out of it that crumbled away while it was sitting untouched! At any rate, 7100 is a no go as expected, missing one slot in the PCB. However the spare 81/110 board slots onto every point, but interference from its mismatched connectors with the port openings of the Quadra. Such keeps it from moving any closer to the backplane. So it's fine for testing HPV Card fitment. but for that setback.

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Belay the instructions above, should have looked at the exploded diagram first. The vertical structure makes that approach impossible.




Looks like the only way to do this without the utter destruction pictured below might be to go all the way thru from the bottom.  I'd use a up-cut type metal cutting bit in the Roto-Zip. I'd pre-drill holes on either side of the structure of the foot along the cut line to stop the cut by feel. topside can be filed out or Dremeled to an appropriate depth at those points, retaining that structure intact to tie the sides of the cut together at that point.


And now for the Ugliness! [}:)]  _________________________________________________________________________________________________


Decided to bust off a bunch of clips to have a good look. A couple of clips were already laying on the floor of the case and it bowed out on the back right corner already.




The case supports one side of the MacCoffeeTable so I couldn't care less about the need to bolt this <^%$#)> thing back together! :p


Good news it that I can position the the spare Radius 81/110 board in battery with the ass end removed..







Had to torque things pretty good to get a slot approximation




This G3 board has a bad passthru cable so I went ahead and used a hair dryer to bend it more into the proper curvature.


Here's the best of the shots of the clearance necessary to do the hack.




Hole for the pins on the connector can be drilled in the PSU shelf from above or with a right angle drill from the bottom to hold the bottom of the card/cable in place. Looks like pins through the top mounting holes of the card will hold it up tight to the PSU shelf. That would allow for fairly easy installation/removal  .  .  . or likely not.


Hack's not really practical with these NewerTech cards. The Sonnet rig is a lot more flexible for this hack from what I recall. Having the longer, active component cable plug into a slot on the Crescendo/NuBus beats the shot, hardwired cable on the MAXpowr boards. The cables aren't all that reliable, having a tendency to fail as on this card from my hoard.

Edited by Trash80toHP_Mini

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I finally got these two onto an open bench and they look like a nearly identical case, save for this little retaining clip structure on the 8100 that I can't discern the purpose of (perhaps more interesting are the presence of stabilizing arms that look like they hold a card in place in the 840AV, where there is no slot present on the motherboard. The right clip was retained on the 8100 to hold the PDS card, while the left clip was deleted to make way for the slot opening.) Despite this retaining plastic, the PDS card itself narrowly fits into both cases. It appears there's a pretty enormous waste of space in that female computerbus connector. There seems to be enough height between the case floor and the table beneath to carve out a slot to accommodate the top of the upside-down PDS card. Because of the video port position, this may mean sacrificing the lock port on the back, but there may still be a better way.













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