Question

Computer Archieture

1. C Programming Language was developed in 1970’s, but why the classic 1980’s arcade game “Donkey Kong” was still written in an assembly language?

2. One day, when Peter is copying some files from a USB flash disk to the hard disk of his PC, the power of the PC is suddenly cut off. Next time when he turns on the PC, its operating system starts to check the file index and the bitmap for consistency. Why the file index and the bitmap must be consistent?

3. Spanison, an America-based semiconductor company, has developed a voice processor for human-computer interaction. The processor uses custom-designed logic and high speed memory to process the voice signal from the human users. What kind of parallelism best describes this voice processor?

Answer 1

Answer of Q 1.

• In computer system the video arcade games were introduced between year of 1970’s to 1980’s and during this many video games were developed like Donkey Kong, Defender, Pac Man etc.
• All these games were hand coded in assembly language by assembly programmer.
• As we know that the C language was developed in the year of 1970’s but it is not preferred for this game coding because of following reasons:

1. Assembly language requires less mapping distance for execution than the C language.
2. The translation time is faster in assembly language than the C language.
3. Assembly language easily allows access to assembly instruction but in C language the compiler don't know about it.  
4. Assembly language easily readable by the processor and C language easily readable by the human being.

• Hence the speed of performance was quite good in assembly language as compared to C language.

Answer of Q 2.

• To check the consistency of file index and bitmap two types of tables were used:

1. Free block table
2. Used block table

Following steps were performed during the block consistency checking:

• In this checking type first step is to read all i-nodes and then increment counter of the used block.
• In second step to reads the free block (bitmap) and then increment its corresponding counter in each free block.
• Following figure a) and b) shows the functioning of it, as shown below:

• Following steps were performed by file system after consistency check:

1. Consistent: It means each block have 1 in either free or used blocks table.
2. Block missing: If block does not appear in used table then it included in free block table.
3. Block duplication: If block listed more than one then rebuild the free list
4. Data block duplication: If same block is used by two files then allocates new block and copy the contents to new one.

• In this way the file index and the bitmap must be consistent in file system.