Look at this USB option for Amiga 1200 Motherboards from Centurion Tech
amigakit.com - Amiga to USB Mouse Adapter: http://amigakit.amiga.store/product_info.php?products_id=12699 Features a 9-pin connector to plug into the Amiga's mouse port and a USB socket where a modern USB mouse can connect. Unlike lower
TIKUS USB Maus / Joystick Adapter (für Amiga, ST, GEOS)