Depending on the BIOS, you could attach a drive with an IDE (host
facing) to SATA connector and a small drive to the system.  This
probably would have to go to a second IDE port, so both could be
independent of each other.
Image the 420mb drive to the SATA drive, and remove it.
Jim
On 1/13/2015 3:29 PM, Mouse wrote:
    If the original machine boots, there are many
possibilities.  I once
 did a linkup with a system with NO serial or parallel ports ([...])
 by bit banging an LED on the console and picking the bits up with a
 phototransistor connected to some parallel port pins. 
 I hate to think how long it
would take to transfer a 400MB drive using that $ 
  Don't forget, with a
technique like that there is no need to limit it
 to (eg) serial-port speeds; the limitations will be the software on
 each end, the response time of the LED, and the response time of the
 phototransistor; these might well permit megabit-plus rates.
 420MB at one megabit, unrealistically assuming no framing or error
 loss (ECC, retransmit, whatever), is under an hour.  Cut the speed to
 100Kb and double the data for framing and error loss, and my
 calculation says 19.57+ hours, still less than a day.
 I don't know about the original poster, but I wouldn't consider that
 out of the question at all.
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