I used to use DSLRFocus for all my acquisition, however, now that I have the modified 40D/5D Mark II, these aren't supported (I understand that Chris Venter is working on a new version, but, until such time...), so looked around for an alternate bulb control program. Enter DSLR Shutter.
I'm a little confused as to whether one really needs the Shoestring Astronomy DSUSB in order to have DSLR Shutter control the newer Canon cameras that only have USB ports for control/data transfer.
Do you have a link or a recommended name for the serial port adapter/release? I built my own cable (serial port->USB->2.5mm stereo) for the 350D and if there's instructions around for a USB->USB system, I'd be happy to have a go at building one. I'd rather save the $100+ (or whatever it costs nowadays) that the DSUSB costs unless it is ultimately necessary.