Use the blue cable. That the Classic boots with the blue cable is a good sign, likely a missing driver causing non recognition. There is no termination switch on the Zip 100 plus. Just leave the second female bulkhead passthru connector unused for initial debug. When the Iomega driver is fully decompressed it will not have that .sit suffix, just the name Iomega Driver. It could be that you need to select the Iomega.sit after using your second method of transfer and invoke one more round of Stuffit decompression either by double clicking or a Stuffit menu pulldown. There is perhaps the possibility that a later version of Stuffit created the .sit than you have running on the Classic to decompress it. But even simpler, should you be fortunate to have your CDROM drive finally working and any of the following install CDs, you can try (no guarantee) various uncompressed versions of the Iomega driver extension simply drag and drop copied from: CD Extras folder within MacOS 7.6.1/8.1/8.5/8.6; or Extensions folder within System Folder MacOS 9.0.4/9.1