Atarimax Maxflash USB Cartridge Programmer
Maxflash Cartridge Programmer and Cartridge Bus Interface with USB Interface
©2015 Steven J Tucker
Chapter 8: Getting Software to Use with your Flash Cartridges
Many internet sites offer Atari 8-bit Software Archives.
Links (will open in a new window or tab)
Also please check out the Flash Cartridge Discussion Forums, other users may be able to point you in the right direction.