Loading IOS on a switch or router via the console

If the flash has been deleted / formated and there is no IOS on the switch or router, you have to copy the new IOS via the console port. this article explains the procedure using teraterm

rommon 1 > xmodem -c filename.bin
Do not start the sending program yet...

        File size           Checksum   File name
 18699016 bytes (0x11d5308)  0x7234    c2600-is-mz.122-15.ZJ2.bin (bad checksum

0x6683)

WARNING: All existing data in bootflash will be lost! Invoke this application only for disaster recovery. Do you wish to continue? y/n [n]: 'y'
Ready to receive file filename.bin ...
now send file by clicking in file-> transfer-> xmodem