Hello Stelios,
>My other iMac G3 has 9 Os but dosnt seem to recognize the external floppy drive.
You could perhaps check whether a special driver is available/needed for that model. It ought to work without, but you never know with USB. Does System Profiler detect the drive as such (do not expect anything on the Desktop until a floppy has been inserted)? If someone you know has a powered USB hub, it may also be worth testing (in order to guarantee the best possible power supply to the drive).
>If i can use this usb external drive i have all the system 7.0 downloaded and i will try to make floppies to install it from the begining.
It is usually better to create properly sector-copied floppies on the old Macintosh computer (with the built-in floppy drive). A USB floppy drive connected to the iMac G3 would then be used for plain transfers to the Classic. Keep any MacBinary (.bin) or BinHex (.hqx) encoding intact as long as possible, preferably until on the Classic, where StuffIt Expander (see below) can be used for the decoding.
A fresh System 7.0 can be downloaded from Apple, but System 7.0.1 may be a better choice (2 MB of RAM is the absolute minimum, I would recommend 4 MB)
http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/System/Older_System/System_7.0.x/System_7.0.smi.bin
http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/System/Older_System/System_7.0.x/System_7.0.1.smi.bin
http://support.apple.com/kb/TA28534
Both system software downloads are approx. 5 MB. If sector-copied floppies are to be made on the Classic (from the .smi contents), the large downloaded (.smi.bin) file will have to be segmented before the transfer on floppies. I do not know whether the shareware program SplitIt (2.0) will work under Mac OS 9, but you may want to test it. Once on the Classic, the file segments can be joined.
http://archive.info-mac.org/_Compress_&_Translate/
http://archive.info-mac.org/_Compress_&_Translate/00cmp-abstracts.txt
>i dont have access to a PC except the fact that i can go to some friend and prepere a diskette there.
You will need an appropriate version of StuffIt Expander for the decoding on the Classic. You could ask your PC friend for help here:
With access to a Windows PC (capable of running a DOS program) with a floppy drive, try the following. Go to http://rrzs42.uni-regensburg.de/Macintosh/files/macftp.html and download the MACDISK.EXE file. Then, prepare an empty 1.44 MB PC-formatted floppy via the FORMAT A: command under DOS or the "full" formatting option under Windows (do this even if the diskette is new and empty). Run the MACDISK.EXE (DOS) program on the PC. Follow the instructions on screen. The result will be a Mac-formatted (sic!) floppy complete with a ready-to-use StuffIt Expander 4.0.1 installer for Macintosh that can be used to install the utility on the Classic.
Now, you could transfer Disk Copy 4.2 (a .bin file) from the iMac G3 to the Classic (Disk Copy 4.2 is used to create exact sector-copied floppy disks from images, via the Make A Copy button).
http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Disk_Copy/Disk_Copy_4.2.sea.bin
A Network Access floppy is useful (will work as a startup floppy, which can be used if/when one wants to mount .smi files). Create the floppy on the Classic using Disk Copy 4.2.
http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Network_Access_Disk_7.5.sea.bin
Do not hesitate to post back for additional information.
Jan