A hazard is created whenever there is a dependence between instructions, and they are close enough that the overlap caused by pipelining would change the order of access to an operand. Our example hazards have all been with register operands, but it is also possible to create a dependence by writing and reading the same memory location. In DLX pipeline, however, memory references are always kept in order, preventing this type of hazard from arising.
It was actually a few years later, in the year 1898 to be exact, when this idea had taken its existence. Vlademar Poulsen was the person who had invented the earlier concept of Oberlin. In 1928, Fritz Pfleumer developed the magnetic tape. But it was not that compact as how the modern cassette player was.
Why 78, 45 and 33 1/3 record formats? 1.78s: (c. 1900 - 1960) The first disc format was the 10-inch 78 rpm record, pictured above in the center, invented around 1900. The first record player was invented around 1870 by Thomas Edison, but this used cylindrical records about the size of an empty toilet paper tube.