Fundamentals Questions and Answers

Answer: A

Correct answer: Temporary, permanent

Memory (RAM) is working space: fast, directly addressable and volatile, so its contents vanish when the power goes. Storage (disk) is slower but keeps its contents permanently, and is much larger. Anything to be kept must be saved from the first to the second.

Answer: C

Correct answer: Both of above

A magnetic disk supports both. Its read-write head can be positioned on any track, so any record can be reached directly in about the same time; and records can equally be read one after another in order, which is sequential access. That combination is what made the disk displace magnetic tape, which allows sequential access only.

Answer: C

Correct answer: Eight bits

A byte is eight bits, which gives \(2^8 = 256\) distinct values - enough for one character in ASCII or EBCDIC, which is where the size came from. Four bits are a nibble, and sixteen bits a word on many machines.

Answer: B

Correct answer: ABC

John Atanasoff and his student Clifford Berry built the Atanasoff-Berry Computer at Iowa State between 1937 and 1942. It was the first machine to use binary arithmetic and electronic switching, though it was neither programmable nor fully automatic.

Answer: A

Correct answer: Extended Binary Coded Decimal Interchange Code

EBCDIC is an 8-bit character code developed by IBM for its mainframes, extending the earlier BCD scheme. It is a rival of ASCII, and the two are not compatible - in EBCDIC the letters are not even in one contiguous run, which is a nuisance when sorting.

Answer: B

Correct answer: Hard Disk

Of the four, the hard disk holds by far the most - hundreds of gigabytes to many terabytes, against 1.44 MB for a floppy and about 700 MB for a CD. It also has the advantage of being rewritable and fast.

Answer: C

Correct answer: 1000th of a seconds

Milli- means one thousandth, so a millisecond is \(10^{-3}\) seconds. The scale continues: microsecond \(10^{-6}\), nanosecond \(10^{-9}\), picosecond \(10^{-12}\) - the units in which memory and processor speeds are quoted.

Answer: A

Correct answer: ABC

The Atanasoff-Berry Computer was built to solve one particular kind of problem - systems of simultaneous linear equations - so it was a special purpose machine, and it was not programmable. ENIAC and EDVAC were general purpose.

Answer: D

Correct answer: None of above

A CD-ROM is an optical medium: data is read by a laser detecting pits burned into a reflective layer. It is neither semiconductor memory nor magnetic, so none of the three categories offered fits.

Answer: D

Correct answer: Process description

The process description (or process control block) is the operating system’s record of a process: its state, its program counter and registers, its memory allocation, and the files and devices assigned to it. It is what the system saves and restores at a context switch.