I'm starting this as a new thread to separate it from the other thread on Live USB's, and if anyone thinks it's particularly useful and wants to pin it/move it/whatever they can do.
I've done some further tests and this is the outcome. I've burned a few Puppy ISO's to USB sticks using the latest version of Rufus (3.20) and these are the results:
Bionic 32 - Success, booted ok
Bionic 64 - Success, booted ok
DPup Stretch - Success, booted ok
Fossapup - Success, booted ok
Slacko - Success, booted eventually
Tahr - Success, booted ok
Vanilla Dpup - Success, booted eventually
Xenial - Success, booted ok
You will note I've said "eventually" for both Slacko and Vanilla. With both of these I initially got a message on screen which said "Waiting for Partition - Failed", followed by a load more stuff in red (which went straight over my head), then a line which said "Pausing for 60 secs". After leaving it, for considerably more than 60 secs, they both booted ok.
As these two had been less than perfect I tried them with both Ventoy and YUMI, and things got even more interesting. Vanilla booted ok with YUMI, but with Ventoy it couldn't find the SFS file. Slacko on the other hand booted ok with Ventoy but on YUMI just produced an error message "Failed to load COM32 file", whatever that means.
Few things I should perhaps mention. My own use of Puppy has only been with Bionic, Radky's Buster and Fossa, so I have no particular knowledge of the older ones. I've never had to burn an ISO to CD/DVD so don't know anything about that either. I also don't use any fancy, expensive, USB sticks. They're all common everyday Kingston, Transcend, etc.
For the purpose of these tests I've stuck with Mainline Puppies, but if anyone wants me to try a specific Puppy shout up and I'll give it a go. I retired last month so I've got some spare time nowadays.
Lastly, if you are trying to create a Live USB and are having a problem please remember to state exactly which Puppy it is, what Operating System you are using, and what software you are trying to burn it with. Without all that info we won't get anywhere.
Thanks