Ok so after messing around this morning it looks like the largest Plus-bootable drive you can create on the SCSI2SD with any version of Apple HD SC Setup is 40mb. At least without hacking/patching Apple HD SC Setup. This is because Apple HD SC Setup checks the SCSI2SD volume to see if it's an Apple HD, same as Drive Setup does. (See Clopes66 earlier post.) So ignore most of that list of drives I posted earlier, the only "generic" drives that are supported by Apple HD SC Setup are the same 40mb Seagate drives in Clopes66's post. And you must use Apple HD SC Setup to initialize the drive or else the Plus will not boot from it. Using Drive Setup seems to be the the most common mistake everyone, myself included, has been making. The other clue I found here: http://www.codesrc.com/mediawiki/index.php/Mac_Plus   I have a 16gb SD card in the SCSi2SD set up as three drives. A 40mb for the Plus boot drive, a 1 gig for Plus storage, and a 9 gig for other Macs & stuff. (The Plus will mount all the drives but only "see" 1 gig of the 9 gig drive.) Depending on the size of your SD card and preferences you can configure your SCSI2SD drives differently. (Note, I am using the new 4.8 firmware with a SCSI2SD v.5.) The 40mb drive I initialized with Apple HD SC Setup. I tried the later 7.3.2 (I think that's right) version from the 7.5 install and it worked fine, which makes sense since 7.5 supports the Plus. Then I installed 6.0.8 from scratch. (I only have 1 meg in the Plus at the moment, I'd rather run 7.1, you should be able to use any OS that supports the Plus.) I used Drive Setup to initialize the other two drives. So this setup worked for me. My Plus has the "v3" ROMs, I don't know if having the earlier Plus ROMs will make a difference. So here are the settings I used for the SCSI2SD. At one point I added spaces in front of the "ST1917" product ID. I don't think that's necessary I just haven't changed it since it worked. Make sure to check "Auto" for any drives after the first one before you save the settings or you'll get an error. Anyway, hopes this helps some of you.