I have mostly succeeded in loading chdk and ptp to use my Canon S5 IS as a web cam that will take images very 30 seconds or so for as long as it lasts

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I would like to have it save the image directly to the hard drive of the PC that the USB cable is connected to. I have ptpcam installed and working fine. I even installed the GUI version and can control the camera that way. I can basically do everything I need with the provided scripts EXCEPT bypass the SD card. From the ptp-extension page of the wiki:
Remote shootingEdit
CHDK 1.2 added support for saving images directly over USB, without saving on the SD card. This is supported for raw and DNG on all cameras, and for jpeg on some cameras. For raw and DNGs capturing a subset of rows from the raw framebuffer is also supported. I want to bypass writing to the card to avoid so many write/erase cycles. I know that would wear out the card fairly quickly. I haven't found a way to do this yet. If anyone has the answer, I will be forever grateful! Thanks in advance!
Flessan