Dan,

I was referring to a parallel cable between the parallel port board I added to the Pi and the camera. Sorry if I wasn't clear - I gave up trying to find a USB to parallel converter that works with the Linux kernel "parport" driver stack. That is what "sbiglpt" (SBIG parallel port Linux kernel driver) wants..

Even if we could find a USB converter, I think it's likely not to work. The sbiglpt "bit bangs" its protocol, polls bits on the parallel port in busy-loops, etc.. If access to those bits becomes a USB hop away, there may be issues meeting the camera's timing, busy-waiting too long in the kernel (or timing out), etc..

There are all manner of fun projects possible here though, such as replacing the raspberry pi in my solution with a microprocessor that speaks SBIG's USB or ethernet protocol on one side, and the camera parallel port protocol on the other. However that involves some reverse engineering of the USB/ethernet protocol and so would be pretty labor intensive. I went with the Pi because it allows the old sbiglpt driver to be reused with minimal effort, and the Pi can serve as an adapter that provides an INDI camera device.

p.s. thanks for the CCD info. I actually bought some class 3 KAF-1600 chips on ebay and took my camera apart. There's a fixed program 8052 clone in there (Philips SB7C752-1N28), a PLD, and a Lattice ispLSI 1016 CPLD. Looks like only the CPLD is programmable so I wonder if chips have to be replaced to upgrade the CCD, or if maybe it's just a matter of updating some EEPROM in the CPLD?

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