But on another mac running os9 it detected the drive. I want to use disk copy because if I just mount the images and drag and drop them to the disk it says there is not enough space.Disk Copy 4.2 was built before USB was even a thought in someones mind Can 10.4 just mount a Disk Copy image when you double click the image (with Disk Utility?) If not you'll have to convert from the Disk Copy 4.2 format to a raw format then write it. I believe you can convert it with something like CiderPress or https://github.com/jonthysell/Convert2Dsk - There are a few utilities to do this from before when FloppyEMU only supported raw disks.
I thought of that but my iMac G4 is one of the newer version that can boot into leopard but not into OS 9Then I'd have to guess it's a limitation of the classic environment. If so boot into OS9, write your disks, and boot back. Or else do the raw conversion and use OSX.