Can I use HD floppies on my Mac II, SE, Plus, or earlier machine?
Some SEs support HD floppies out of the box, as indicated by “Superdrive” or “FDHD” (which stands for Floppy Drive, High Density) on the front of the case. (Note, however, that a very few SEs with the Superdrive or FDHD faceplate may have a motherboard inside them which does NOT support HD floppies because someone swapped out the original motherboard. I have seen one such SE and it was because I pulled the motherboard for use elsewhere.) The Mac II requires a ROM upgrade to support HD floppies. This ROM upgrade essentially makes it a IIx. The SE without HD floppy support can be upgraded with new ROMs and a new SWIM chip to support HD floppies. The Plus can use (though not boot from) HD floppies via the Applied Engineering AE HD+ external floppy drive and the proper drivers, or with an Iomega “Floptical” SCSI drive. The Iomega drive cannot read or write 800K Mac-formatted disks, though it can read and write 720K DOS-formatted disks and 1.4MB floppies of either Mac or PC format, in addit
