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Bolle

Any interest in a SE/30 internal Nubus adapter?

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Some time ago already I had the chance to get my hands on a Radius-made Nubus adapter for the IIsi. (thanks again to @maceffects)

We discovered that this one actually works in the SE/30 so we reverse engineered it. The only technical drawback using this design is that Nubus cards will run at 8MHz in the SE/30 instead of 10MHz that it should be running at.

Most cards I tested did not care about that though.

 

Space constraints inside the SE/30 impose a few more drawbacks when it comes to using the cards internally:

 

IMG_3904.thumb.jpg.87802c2bb8b2d7808aa05002bec0ee2c.jpg

 

-HDD has to be moved out of its original spot

-one mounting tab on the chassis has to be bend out of the way, because the solder points for the Nubus socket would be getting in the way

-no 12" cards (obvioulsy)

-access slot does not line up 100% but should be ok for most cards

 

Good things:

-enough space between Nubus card and floppy drive for a SCSI2SD

-enough space for IIci accelerator slot as well as another PDS passthrough

 

 

What are everyones thoughts?

Better make it an external Nubus breakout-box kind of thing and just run the bare Nubus signals through a (as short as possible) IDC cable to an external box with a separate power supply?

It should be possible to modify the design to use all 3 existing slot IDs which would open up the possibility for three Nubus cards in a box.

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Potentially yes, but it's probably worth doing a poll or something on what hot little SE/30 items you have on the pipeline, to indicate demand and suggested costs?

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I think both are very interesting, but my vote goes to a breakout box. Feels like that opens more exciting and new options.

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I too find both options quite exciting. In the case of the breakout box, I think it'd be a good idea to look for a relatively readily available enclosure, that would fit nicely under the Mac SE/30 itself.

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You don’t need a special chip. The Radius implementation is just a couple of 74-logic ICs and 3 GALs. 

Edited by Bolle

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Dear Bolle,

 

I am interested in effective Nubus adapter; primarily to create  Fast/wide internal bus.  I have purchased a Second Wave ExpanSE/30 that I would like to attach to an Atto SE IV within the chasis of the SE/30.  Ofcourse my power supply would have to increase and I'd need many fans, but Id like to see how you solve this problem.  Also what you got coming in way of an advanced processor upgrade? :)

 

Sincerely,

 

Tpope

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Well, everyone knows I'd buy one :)  I kind of wonder about making an external chassis so we can have a breakout of some kind.  @Bolle if that is do able let me know and maybe I can make a case for such a device. 

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On 8/4/2020 at 8:29 PM, Bolle said:

It should be possible to modify the design to use all 3 existing slot IDs which would open up the possibility for three Nubus cards in a box.

From what I vaguely recall of the Xpanse setup, you'll be utilizing the single NuBus ID line available on the 030 PDS and decoding three NuBus slots within that Slot/SuperSlot space? That should leave two interrupts available within the SE/30 itself, no?

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9 hours ago, Trash80toHP_Mini said:

That should leave two interrupts available within the SE/30 itself, no?

No. Each Nubus card goes into its own slot space and will have its own slot interrupt wired right up to the PDS interrupt lines.

The /NUBUS line on the PDS is just an address decode signal from the GLU that is active whenever any of the slot ranges is addressed.

 

You could split up card space and put multiple cards into one space or do some switcheroo on interrupt signals or whatever but that seems overly complicated.

Nevertheless Xpanse probably went that way.

 

14 hours ago, maceffects said:

I can make a case for such a device

I certainly won’t be making any cases, so I’ll happily leave that task to you :)

 

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