Author Topic: CHEAP USB HOST + PCMCIA CARDS!  (Read 4691 times)

DrWowe

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CHEAP USB HOST + PCMCIA CARDS!
« Reply #15 on: April 21, 2004, 02:45:36 pm »
So, here\'s the deal with PCMCIA vs Cardbus.  PCMCIA is the original standard for laptop expansion.  It uses a 16 bit bus based on the ISA standard.  Eventually, Cardbus came along, and its based on the PCI bus and uses a 32 bit data transfer.  When CompactFlash was standardized, it was basically 16 bit PCMCIA in a smaller form factor.  They did this for convenience, because PCMCIA was an established standard, with a standard way to transfer the ATA command set for storage devices.

Because of this, Intel and other manufacturers include the PCMCIA/CF support in their mobile chipsets.  I think the interface is actually built in to the XScale chip itself.  But there is no Cardbus support.  Also, keep in mind that although Cardbus uses the same physical form factor, the electronic signalling is totally different.  It\'s not just a simple \"extension\".  A Cardbus device is basically just a PCI device, which means a whole PCI subsystem is required in the host, and that would add a lot of extra cost for no reason.

Even if there were a Cardbus controller in the Zaurus (which there isn\'t), there\'s another problem.  The PCMCIA format has 68 pins.  CompactFlash only has 50.  That means that the adapter can\'t map some of the pins.  It turns out that many PCMCIA devices don\'t use the 18 missing pins, which is why they work with the adapter (although not all cards work).  But there\'s very little chance a Cardbus device could work without the missing pins.

arniel

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CHEAP USB HOST + PCMCIA CARDS!
« Reply #16 on: April 22, 2004, 04:56:49 am »
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I couldn\'t find any european supplier that wanted less than 40 Euros

That\'s not too bad, I could live with that, but it does depend on what I could run. Could you point me in the right direction please?

I assume there will be driver issues (just as there are for non-standard CF devices), but for little money I could attach to a wired ethernet and use a modem which otherwise (as CF) cost a fair bit (in the UK at least).

I\'m a little concerened about this cardbus thing though. I\'ll have to do some digging (I\'ve never had to deal with PCMCIA/PCCARD/CARDBUS stuff before) to see whether there\'s enough stuff still available which could work with the PCMCIA adaptor.


Simon

I just searched through eBay, and the only European supplier was from Germany.  In the end, it was cheaper to win an auction from the USA, and pay $15 shipping for a $10 item :-(

I have been successful in running the EZ-GIG card, but as I said, the modem and ethernet cards did not work, even though the ethernet card was recognised.  Attaching to a 100Mbit LAN would have been nice!

AIUI, although Cardbus uses the same connector, they are electrically incompatible - remember, cardbus is PCI equivalent, and PCMCIA is ISA equivalent.  That\'s why cardbus cards cannot be plugged into a pcmcia-only laptop.