Krux wrote:It shouldn't matter.
People have had problems with running 1.20 on a zip drive-equipped machine. But if you did install the latest OS before the reader itself, I doubt you would have a problem as it's not like you will be running the MPC, saving/loading to zip etc under the new OS. You would just load OS1.20 from zip, turn off, and install the card reader.
It is a good idea to install the card reader first without upgrading to v1.20, that way you tackle one (possible) problem at a time. Once the cardreader is functioning correct you can upgrade to v1.20 ( This os AFAIK allows you to use 1G flashcards without the need to divide it into smaller partitions). If you would first upgrade to 1.20 and turn your internal zip drive unaccessible (this has happened b4 to machines with older internal zipdrives) then there is no way to revert to os 1.14 if you have no external scsi drive on which you have a copy of the 1.14 os.