The ARVI is a very powerful
debugging tool if you want to do some
software development on a C-64.
With the built in
machine code monitor, you can stop code
execution at any point and look into memory, start tracing your code, set
break points for when something happens and of course
modify your code on the fly.
Most "
professional" AR users didn't really use the poke finders and spritekillers the cartridge provides, but mostly the
BASIC extensions it provides and the aforementioned Monitor tool.
Nowadays there is a new version of the AR (based on the AR VI) called the
Retro Replay.
That cartridge has an user upgradeable flash rom, more memory than the original AR and it also sports an
Amiga 1200 clockport connector that can accomodate an
rs-232 adapter (Silver Surfer) or an
ethernet adapter.
Yes, you can connect your C-64 to the
Internet using a Retro Replay,
Silver Surfer and the
Contiki OS!