I booted from a laptop hard drive last night (just got all the parts), and that works fine. I put DOS on the drive using a different computer, then attached it to the I-Opener and booted.
I received a message from BadFlash a few days ago that the V5 I-Opener software wouldn't boot using a modified BIOS. Apparently the code checks the BIOS somehow and refuses to run if it is not recognized. So that explains that problem.
I haven't yet "formatted" the SanDisk, but I believe that will work when/if I do. Is there any purpose in copying the current contents of the SanDisk someplace before I overwrite them? Am I ever likely to need them or want them again? Does anybody else have a use for them? Note: This is not a virgin system. It was used online for several months.
My next decisions will be a) what OS to run (Linux or Windows), and b) how to install it onto the hard drive.
I'm leaning toward Linux, and I think I can do that in several steps. I would install a basic, console-only version on the drive while it's in the other computer, then move it to the IO and boot. Hopefully I could include enough drivers to use a USB network adapter. I'll have to look at JailBait and other possibilities. Then I could install more over the network. In that version I think I would use the SanDisk as my /boot volume, just because it's there and so I could save a little space on the hard drive.
OTOH, for Windows I think I would copy the whole CD onto the drive, then boot DOS (as I did last night) and install Windows from the CD image on disk. My disk is only 2 Gb, so it might be a little cramped for that.