In Assembly Language, string operations are typically performed using low-level instructions that manipulate memory directly. Here's a general overview of how some string operations might be implemented:

1. String Comparison:
   To check if a string contains another string, you would need to iterate through the characters of the first string, comparing them with the characters of the second string.

2. Character Counting:
   Counting occurrences of a character would involve iterating through the string and incrementing a counter each time the desired character is found.

3. Prefix/Suffix Checking:
   To check for prefixes or suffixes, you would compare the characters at the beginning or end of the string with the target prefix or suffix.

4. String Concatenation:
   Joining strings would involve copying the characters from one memory location to another.

5. String Repetition:
   Repeating a string would be done by copying the string multiple times to a new memory location.

6. String Replacement:
   Replacing characters in a string would involve iterating through the string and replacing specific characters as needed.

7. String Splitting:
   Splitting a string would require finding delimiter characters and storing the memory addresses of the substrings.

8. Case Conversion:
   Converting case would involve iterating through the string and applying a bitwise operation to each character to change its case.

In Assembly Language, these operations would be implemented using basic instructions such as:

- MOV for moving data between registers and memory
- CMP for comparing values
- JMP for conditional jumps
- INC/DEC for incrementing/decrementing counters
- AND/OR/XOR for bitwise operations

The exact implementation would depend on the specific Assembly Language dialect and the target architecture. Each operation would require careful management of memory and registers, making the code significantly more verbose and complex than the high-level Go equivalent.