Wallstreet expansion bay PCI

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Joined: Oct 5 2004
Posts: 13

According to the developer note, the Wallstreet's right expansion bay connector can be configured to provide direct access to its PCI bus. However, to the best of my knowledge (and Google's search ability), no company ever made products that took advantage of this feature. Has anyone here heard of devices that did?

The reason I ask is that the pinouts for 32-bit 33MHz standard PCI slots and the PowerBook's connector look agonizingly similar -- the PB implementation lacks 3 of the interrupt lines (there's only one expansion device, so that shouldn't be a problem), both the PRSNT lines (also shouldn't be an issue, presence detection is handled through other means), and the power management event line. Since I have spare EBM connectors, PCI connectors, and lots of time, I'd like to determine whether an EBM-to-PCI expansion slot adapter could be built.

Another consideration is the fact that most PCI cards won't fit directly into the expansion bay (there's only 5.25" available in there). Since the PCI bus doesn't use termination, the trace length could be an issue. On the other hand, desktop logic boards often have PCI buses longer than this. Does anyone think the trace length would cause issues if the signal layers were sandwiched between ground layers on the PCB?

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Dr. Webster's picture
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Joined: Dec 19 2003
Posts: 1687
I don't remember the name of

I don't remember the name of the company or the product, but I remember a product that plugged into the PCMCIA slots and provided a breakout box where you could install PCI cards.

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Applefritter Admin

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Joined: Dec 20 2003
Posts: 174
I sold a Wallstreet PCI expan

I sold a Wallstreet PCI expansion card back in June. It had normal PCI slots and plugged into the PCMCIA slot.

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Jon
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Joined: Dec 20 2003
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Instead of hacking in a full

Instead of hacking in a full sized PCI slot, how about using a compact PCI slot like newer laptops? Might they also have dropped a few (the same? Smile ) lines as well...

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Joined: Oct 5 2004
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Re: I don't remember the name of

Yeah, I've heard of those. A company called MAGMA does them, and they also do boxes that plug into PCI slots and provide up to 13 more.

The thing is, those devices are pretty specialised, and are surplus to my requirements. What I was asking about are PCI devices that plug into the right expansion bay (the 5.25" one, for optical drives). There was some talk, when the Wallstreet was released, of a company planning a PC Card cage that plugged into the expansion bay, but I can't find any information confirming that ever happened.

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Joined: Oct 5 2004
Posts: 13
Interesting idea

Thanks for the pointer. I had a look at the cPCI specification, and it's billed as being "electrically identical to the PCI specification". That is, you can use exactly the same bridge chips for cPCI as for PCI.

Unfortunately, they've actually added signals that weren't in the original PCI spec. And, since Apple never built laptops supporting cPCI, I don't like my chances of finding much in the way of Mac-compatible hardware for that format.

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Joined: Aug 31 2004
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not compact pci, mini-pci

cPCI is really more of a spec for embedded/industrial systems. I believe the previous poster meant mini-PCI, which is common in laptop and some small-form-factor hardware. Apple's Airport Extreme cards are, IIRC, minipci-based.

-vga4life