If you choose Direct-Mapped Method the choice of replacement
policy will not affect the process.
Choosing Fully-Associative Method lets you select different replacement
policies and find the best one for the reference string. You can modify
the reference string and construct one that takes advantage of a particular
replacement policy.
In the text area you can see the history of replacements made.
As a result you can obtain the total number of references, number
of hits and misses for a given string.
You are allowed to choose cache size just to experiment
with the idea of improving the hit ratio while increasing the cache size.
The example of applying FIFO algorithm to reference string: 0 1 2 3
0 1 4 0 1 2 3 4 with cache sizes 3 blocks and 4 blocks will
give you a strange result.