TWO SLOT IIsi Nubus Card hack . . . (SE/30 hacks)

[Trash80toHP_Mini]

. . . is a notion I've been sittin' on ever since I finally got the IIsi. It seems that the Gemini Two Slot adapter for the DuoDock is hackable so that the "Upper Slot" in the Duo can be hacked onto the connector or thru-holes for the IIsi's NuBus Adapter Card.

This will entail hard wiring the HDD's Power Cable to get the MoBo pins & shroud out of the way, and maybe a couple of other minor hacks. to the IIsi MoBo.

From the Gemini side of things, the EuroDin Connector to the DuoDock MoBo will need to be desoldered for it to fit due to space limitations in the IIsi, unless the entire bottom portion (a passive straight signal passthrough slot expansion card similar to the PCI adapters for the 5XXX & 6XXX PCI risers) can be lopped off entirely. Machine pins will need to be soldered, socket side down, onto the soldertails of the Gemini's "outer" NuBus connector so the pins will insert into the NuBus Adapter's female sockets.

From the NuBus Expansion Adapter end of things, the only thing I can think of would be removing the digital glue that assigns the Slot ID from the card and possibly replacing the EuroDIN connector with machine pins as sockets to mate with the machine pins soldered socket side down to the underside of the Gemini Card's Outer NuBus connector (as mentioned above) in order to shorten the distance between the sandwiched adapter pair.

The length of the lower card will depend upon the height/form factor of the HDD installed in theIIsi, unless of course I move that, along with the speaker, to the empty space under the FDD that's currently under consideration for a ZIP or DVD installation.

The hardest part of this silly lil' project will actually be modifying the @$$ end of the IIsi with a two (or, preferably, three) slot backplane offset from the existing slot. The third (bottom) of the slots would be used for breaking out the IIsiCrawlspaceCardsHack™ connectors to the outside world.

IIsiCrawlspaceCardsHack™ thread to be posted later. }

 

[Trash80toHP_Mini]

This project is likely a non-starter. The IIsi only has three PseudoSlot IDs, one for the NuBus Card and the other two for the Radius Color Pivot II/IIsi VidCard and the 10bT NIC respectively.

I guess I could forgo the RCP2/IIsi VidCard for one of my Red Radius NuBus Powerhouse VidCards though! )

 

[Trash80toHP_Mini]

Well, thanks to comrade znosko, I've got another pair of Gemini Cards and a pair of working DuDock LoBos to play around with for this and another two projects.

Now to check out the NuBus Standard Documentation for Slot ID hacking!

Has anyone broken ground on this front as yet? :?: I hate carving out new versions opf the wheel when they're already available in the form factor I require. )

< wonders what the 6100 NuBus adapter card looks like? } >

 

[Bunsen]

Almost exactly like a 6100 G3 upgrade, sans heatsink; or indeed like the HPV right angle adapter, DOS card right angle adapter - they're all required to take up the same cubic and present a slot at the same height.

 

[Trash80toHP_Mini]

Figured that. [] ]'> My .TXT conversion was faulty again. :

Pics would be appreciated.

I meant to ask which NuBus Chipset is on the 6100 Adapter and if any of its bits stick up very high. :?:

 

[Trash80toHP_Mini]

I just bought myself a little father's day present. I've got another IIsi NuBus Adapter on the way! [] ]'>

The original one will stay stock, but this one is headed for the soldering/de-soldering bench for a couple of address line rearrangements and a Gemini Card graft in the 2-Slot hack attempt.

Slot 1 - Rocket/SCSI II DaughterCard

Slot 2 - Futura VidCard with 10basetT Daughtercard

PDS undercarriage hack - Radius Pivot II/IIsi Card . . .

. . . or somethingorother . . . [}] ]'>

 

[Charlieman]

I'm interested in this project, Trash, but can you explain it from the beginning.

I am not familiar with the Gemini card but I will start reading your other project thread: viewtopic.php?f=29&t=17721

 

[Trash80toHP_Mini]

Get one of the DuoDock service source PDFs and take a look at the exploded diagram. The Gemini Twin Slot Adapter is a passive 180 degree adapter that drops the Dock's two slots below and underneadth the MLB of the DuoDock. It has a reversed gender connection to the Logic Board that I'll be removing, once/if I can get the two slots working in the IIsi, so that I can get the lid closed.

There will be a horizontal offset of the NuBus Card's location by approx. one connector's height, but nothing a new BackPlane cover can't address. I've got a mint empty case for the final version of this cards sprouting every which way hack. I might graft a second backplane opening from the first case underneath the stock slot in the mint case.

Dunno, it's interesting intellectually and mechanically challenging. What's not to like? :approve:

 

[Trash80toHP_Mini]

I'm not so good with words when it comes to describing my hackin' plans . . . but graphics? :?:

'

I've added just a single row of pins for the NuBus Connector's to the graphic for clarity's sake. There are a couple of ways to go about this for the final version. For starters, I'll solder "Machine Pin Header Strips" onto the soldertails of Slot C (Pseudoslot Address: $C) so I can just plug the full height Gemini Card straight into the IIsi NuBus Adapter's Connector. At this point, the top slot should be connected to the $F Address Space and Interrupt of the IIsi Adapter Card's Slot $F.

Hijacking another Interrupt/Address line to implement the second NuBus Slot will be the fun part of the hack! :approve:

Dunno, we'll see, that's why I've got a spare NuBus adapter and several spare Gemini Cards. [}] ]'>

If things work out well in the proof of concept stage, I'll do my best to muck it up by removing the upper section of the Gemini Card as shown on the right. For starters, the gender changed DuoDock connector and the top 2/5 of the card will remain intact. This will stick up about an inch higher than the top of the IIsi Case would be if it were in place.

If all goes to plan . . . : . . . I'll probably order a NuBus EuroDin Wire Wrap Socket. I'll remove the top slot's connector from the Gemini Card. Soldering the wire wrap connector to the Gemini Card first will allow the slots to be tested again in the NuBus connector on the IIsi Adapter. If all works at that stage, the Connector on the IIsi Adapter will be removed and the Wire Wrap pins will be inserted as deeply as possible (the crystal Can is the highest part to clear) into the vacated NuBus Slot's ThruHoles and soldered into place and the extra wire wrap pin length will be clipped. At this point, the pair of Gemini Card Slots will only be offset about a quarter of an inch farther from the NuBus Adapter PCB than the original, single NuBus Slot.

I'll do an edge on view of the Hack as soon as I can get around to it. The figures in the IIsi DevNote for the edge-on/cross sectional view of the NuBus Adapter, MoBo and NuBus Card are pretty rough and not done to scale at all.

I hope this clears things up just a bit.

 

[Trash80toHP_Mini]

I played around with the NuBus Adapter Diagram from the DevNote and wound up doing a major overhaul.

This diagram shows both the NuBus and Basement PDS hacks, both done by soldering Machine Pin strips to the soldertails of the Gemini Card and the IIsi PDS respectively. One of the two cards mentioned will have its Right Angle PDS Male Connector removed and replaced by Machine Pin Strips in their standard configuration as high reliability sockets on a PCB.



Lets see if this clears anything up! :

 

[Trash80toHP_Mini]

OOPSIE! :-/ I'll have to do an update on the graphic, I forgot the PDS Slot Connector on the Isi MoBo and a few other things.

If I had a spare IIsi MoBo ,I'd probably remove the soldertail connector with a wire wrap connector and permanently solder the SuperMac PDS Adapter with its Zeners Implemented onto the extended pins rather than doing the Machine Pin Hack . . . I just may do it anyway . . . time to order a couple of PDS and NuBus Wire Wrap EuroDin Connectors . . .

. . . that'll be the most reliable and compact I/O hack overall . . . if a bit riskier! [}] ]'>

 

[Trash80toHP_Mini]

Last update for this thread, my discussions w/bbraun abut the addressing issues of both of these I/O hacks are over in the main SuperIIsiHack™ AKA SE/30's BANE . . . thread

View attachment 16244

I've switched to a more aggressive hack of the IIsi MoBo by substituting the original soldertail PDS socket with a Wire-Wrap Socket that will join the Hacked SuperMac adapter to the Hacked SuperIIsi's Mobo permanently for the Basement PDS Card Hack. I've decided that going half-way using the "Machine Pin Hack" would be reversible, but less robust physically and therefor less reliable electrically.

The same holds true for the marginally less risky, but equally aggressive, removal of the NuBus Connector from my spare NuBus Adapter. The cut down Gemini Card (DuoDock Donation) will have its Male NuBus Connector replaced with a soldertail version as well, after this is fully tested in the unmodified NuBus Adapter's Slot, the NuBus Slot will be removed and the extra length pins on the wire wrap connector will be permanently soldered to the NuBus Adapter slot's pads.

Please let me know if this diagram is self-explanatory.

Do I need to show the NuBus Slot Hack alone for simplicity or is the combo graphic sufficient?

Might it be clearer with both posted individually?

 

[Trash80toHP_Mini]

It feels great to have some time to play around in Illustrator 8 without being back in the production harness again!

View attachment 16246

NOTE: ATX Power Supply Hack required for more than 15W draw.

Here's a version of the basement expansion ploy that might not tax a stock IIsi's PSU.



I'll post this in a different thread of its own with the proper title for any PowerCache jockeys with a IIsi to play with. [}] ]'>

 

[Bunsen]

Please let me know if this diagram is self-explanatory.

Hey Trash80 - your diagrams help a lot. Keep it up

One question - why is the passive SuperMac PDS adapter even in there, as opposed to mounting the machine pins directly on the back of the Pivot card? Just want to keep your mods off of active/working cards?

What interests me is - whether the basement approach could work with an SE/30 - with suitable chassis modifications of course.

 

[Trash80toHP_Mini]

Thanks for the feedback mate! I was really hoping they'd help clear up the muddiness of my .TXTual ramblings.

I've added the "passive" SuperMac Adapter Card into the mix for a few reasons.

1) The thruholes for the unimplemented Zener Diode Packs are shown as populated, which provides over-voltage protection to the entire PDS chain. SuperMac decided this protection was unnecessary for their IIsi Video Card, but I'm making an attempt at adding a lot more circuitry than a single VidCard to the PDS.

2) I haven't looked at the changes in trace length that might be a side effect of changing the direction of the PDS connectors yet. It doesn't seem to have any effect upon the function of the Radius Color Pivot II/IIsi, but I haven't modified one of them for straight "stacking" the NIC or tested its function yet. The SuperMac Adapter's traces could be cut and patched to correct any timing issues should they arise.

3) Similarly, the "passive adapter" makes a handy "breadboard" for cutting and patching traces to re-arrange address/interrupt lines or implementing them on N.C. pins in the PDS spec. The latter will likely make timing for the "second NuBus slot" an issue, but a reversible, ugly, unreliable/noisy proof of concept hack on an inexpensive basement level board beats mucking around with the NuBus Adapter Card's traces by a large margin!

4) Strain relief. This is less of an issue now that I've decided to use a "wire wrap replacement socket" approach, but it is/was important for the less robust "machine pin hack." Four standoffs mounted to the thin, clear plexi "basement floor" makes swapping the PDS expansion cards around down there a lot less likely to induce borkage.

I'll have to give the SE/30 notion some thought, offhand I'd say the approach would be considerably less advantageous.

 

[Trash80toHP_Mini]

Yo, B! I may have a workable notion for taking this hack to a new level for the SE/30! [}] ]'>

 

[Charlieman]

Bunsen added:

What interests me is - whether the basement approach could work with an SE/30 - with suitable chassis modifications of course.

I was thinking along similar lines. If you mounted an Apple HD20SC enclosure underneath the SE/30 chassis, you could could create an "invisible" enhancement.

 

[Charlieman]

Thanks for the pictures, Trash. My only concern is that with so many redirections, it is difficult to keep track of Pin 1.

 

[Trash80toHP_Mini]

Don't worry about pin one, I've kept it and the rest of them "straight."

Look at it like this:

The first card is just flopped over from 90 degrees to flat onto the mobo, pin one is still pin one, the legs of the right angle connector are like the rings in a binder, the pages stay aligned on the rings as the connector wires do to the card and MoBo. You've just closed the half-open binder.

In a binder, you can remove a page and clip it behind the next page, that's the transition of that first card into the "basement" where it's still aligned with the MoBo Page on the binder rings.

As far as the "Left Angle Connector" replacements go, you're just laying the binder out flat from its halfway open position, all the holes line up with the original rings, it's just that more of the rings are exposed.

Does that help? :?: