These are the Amiga Flasher programs.  

Be sure to get the appropriate flasher for your modem  (VFC or V34).

It has been tested on a number of different machines and should work on yours.

The only possibility of a problem might occur if you have a 500 or a 2000 that 
is very old or very abused and the serial ports are not stable.  The current 
release of the Amiga flasher will attempt to flash the modem at 38,400.  As the 
flash progresses you should see an "*" appear somewhat regularly until there is 
a complete row of them across the window.  In the event that the flash fails the 
only real indication will be that you haven't seen a new  "*" appear for a LONG 
time (give it a while it does take a few minutes to complete the flash).  If it 
does fail (that is what the abort button is for), power cycle your modem (off 
and on), then run the flasher again.