Somehow, you need to perform some magic. Over the air and magically, you need to install a utility (eg PC Exchange) which will read DOS/FAT formatted floppy disks on the PowerBook. Or maybe somebody local can supply a copy on disk.
You could try a utility such as MacDrive on the Windows 7 PC. This would allow you to write HFS (Mac format) floppies. Off the top of my head, I don't know whether there are any HFS drivers which work with 64 bit Windows.
But you've got a working IMac...
1. Write the data to a DOS/FAT format floppy on the Windows 7 PC using a USB floppy drive. Spend a tenner plus postage for any USB floppy drive. You don't need the Imation drive.
2. Transfer the the USB floppy drive and data to the iMac.
3. Format a new floppy disk as HFS on the iMac and copy over the data.
4. Transfer floppy disk and data to the PowerBook. There's a gotcha here. The files will be packed as HQX or SIT, so you will also need to transfer an unpacker to the PowerBook. Most of the time you will be able to do it on the iMac, until an unpacked file is greater than 1.4MB.
To get stuff this way from Windows 7 to your Mac Plus will require an extra step. The Plus cannot read 1.4MB floppy disks and the USB floppy drive cannot write 800KB floppy disks. You'll have to perform an extra exchange via the PowerBook.
You could try a utility such as MacDrive on the Windows 7 PC. This would allow you to write HFS (Mac format) floppies. Off the top of my head, I don't know whether there are any HFS drivers which work with 64 bit Windows.
But you've got a working IMac...
1. Write the data to a DOS/FAT format floppy on the Windows 7 PC using a USB floppy drive. Spend a tenner plus postage for any USB floppy drive. You don't need the Imation drive.
2. Transfer the the USB floppy drive and data to the iMac.
3. Format a new floppy disk as HFS on the iMac and copy over the data.
4. Transfer floppy disk and data to the PowerBook. There's a gotcha here. The files will be packed as HQX or SIT, so you will also need to transfer an unpacker to the PowerBook. Most of the time you will be able to do it on the iMac, until an unpacked file is greater than 1.4MB.
To get stuff this way from Windows 7 to your Mac Plus will require an extra step. The Plus cannot read 1.4MB floppy disks and the USB floppy drive cannot write 800KB floppy disks. You'll have to perform an extra exchange via the PowerBook.