Hacking the PDQ HDD Connector - need insight

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doug-doug the mighty's picture
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Hacking the PDQ HDD Connector - need insight

I have a PDQ and I am trying to upgrade the internal HDD.  My plan is to go with a 128GB CF card plus a CF-IDE adapter.  I have in fact purchased one which allows dual CF cards on the device.  When conected to a USB adpater, I can see both drives (128GB CF Cards) on the USB as a master/slave configuration.  I infer from this that the device works as advertised.   I cloned my HDD over to one of the cards (master slot) and all went well.  The device intends for the drives to be device-selected and internally assigns master/slave designations.  It has 44 pins only.  The jumper pins are being internally set within the device.


When I insert this device into the place where my PDQ HDD belongs, all is well.  I can boot from the device (128GB CF Card in master slot) however, it only see that master slot.  The slave slot is not found at all.  I note that the stock PDQ adapter (HDD to mother board) which I am plugging into has 60 pins (44 plus 4 for the expected jumper selection choices).  With my CF adapter device plugged in (proper pin alignment confirmed), the four jumper pins slots are left open/unconnected.  When the original HDD is plugged in, the jumper pins connect to the motherboard adapter.


From what I can tell, the motherboard adapter is passing the jumper pins back to the motherboard (when a 60 pin drive is plugged in) and the motherboard may be setting the pins this way.  This is confuising to me given that the pins, left open, would default to a simple master drive via cable select.  So with my CF adapter device plugged in to the motehrboard adapter, I expect to see both CF cards.  It seems the motherboard is thinking I have only one drive attached.


Can someone validate this for me?  My block diagrams for the PDQ do not go into this level of detail.  Is there a way I can circumvent this and force the motherboard to see both drives?  If it is a matter of lifting a jumper component on the motherboard, I can do this.  If it is a matter of cutting a trace on the motherboard, I am leery.  Hopefully there is an easier answer.  Do I possibly need to insert a wire jumper to cross-connect the jumper pins and trick it into seeing the second drive?