Strpos is entered with the Index register pointing to the search string, and the A accumulator with the character search value. This routine is used to find the starting address of a substring within a larger string. It accepts a source string pointer, and a pointer to a substring. It returns the address of the substring, if not found it returns address zero. This routine inserts a substring into an existing string.
Most versions overwrite existing characters.
It accepts a pointer to the source string, a pointer to the substring to insert, and a numeric value representing the start position where insertion should begin. The routine should return a numeric value representing the number of characters inserted. This routine reverses the characters in a string. It accepts the address of the string. It accepts the address of the string.