ET VOL 6 CH 6,7 Flashcards
Which of the following items is stored in main memory?
Data, programs, calculations, and operands
Time interval from the instant a request for data is initiated until the data is available for use.
access time
The output side of a flip-flop is read from memory without having to be rewritten
non-destructive readout
The power to the computer is turned off and the contents of memory are retained.
nonvolatile memory
The particular location of a larger memory array where a packet of information is located.
memory access
Power is shut off to the computer and the contents of the semi- conductor memory are lost.
volatile memory
The data is lost when it is read from memory.
destructive readout
A memory unit that can receive requests from more than one CPU or I/O section is known as which of the following types of memories?
Multiported memory module
Pcb type memories are usually composed of which of the following memory types?
Semiconductor
In a typical square form memory, the intersection of an x row and y column is called a
memory word address
The x rows and y columns of a typical memory will be equal in number.
true
Memory operations in most computers usually include which of the following items?
- Control circuits 2. Timing circuits 3. Memory cycle
Memory interface circuits include which of the following items?
Communication lines Interfacing register
A word is read from memory, then rerouted back through the Z register to be rewritten. This is what type of memory?
Destructive readout
Priority of memory requests are evaluated by which of the following devices?
Control circuits
Memory read/write enables are provided by which of the following devices?
Timing circuits
what is the memory cycle
read/write
During a complete memory cycle, the first thing that must occur is which of the following?
Memory address translation is accomplished
main memory is also called
ROM
To locate a memory address word, the computer uses which of the following items in memory?
Memory logic
The conversion from a logical to a physical memory address is a function of which of the following items in memory?
Memory logic
In all computers, for every read operation there will always be a corresponding write operation.
false only in destructive memory
In order to increase memory speed using interleaving, which of the following items are required?
More complex CPU and memory control circuitry
When odd parity is used for memory fault detection, all words stored in memory will have which of the following bits?
An odd number of set bits stored at each memory location
The memory protection register set is used for which of the following purposes?
To restrict read/write operations in portions of memory
In a memory segment within the protected area with all three bits of the memory protection control register set, which of the following operations are allowed?
- Execute protected 2. Write protected 3. Read protected
Memory lockout is used by larger computers to prevent access to particular areas of memory by task state instructions. Which of the following describes the lockout function?
It is disabled when the CPU enters a particular executive or interrupt state and disabled when the CPU enters the task state
Compared with semiconductor memories, magnetic memories have which of the following advantages?
They require less power and they are nonvolatile
The state of a core or film is changed by which of the following conditions?
Current flow in the opposite direction of sufficient magnitude to overcome the magnetic field and to magnetize in the new direction
Compared with core memory, film memory has which of the following advantages?
Increased speed of read/write operations and less power required 2. More compact and durable 3. Twice as many memory cells can be put in the same space for the same amount of power
Each ferrite core can store what total number of bits?
1
In a four-wire core winding, what is the physical make up of the windings that are strung through each and every core?
2 drives lines, 1 sense line, and 1 inhibit line
What Detects the change in state of the core from one to zero.
Sense Line
What Each line provides 1/2 of the current necessary to change the state of the core.
Drive Line
What Prevents changing the core from a zero to a one.
Inhibit Line
In a three-wire core, this line performs the same function as in the four-wire core.
Sense
To simplify addressing, reading, and writing operations, magnetic cores are arranged in which of the following ways?
In matrices
Which core in an array will be switched from one state to another?
A core with a full read or write current passing through it
In a core array the inhibit line is threaded in (a) with the x or y drives (series, parallel) lines and the sense line threaded through (b) core. (each, every other)
(a) Parallel (b) each
What is the basic building block of the memory stack?
Memory Plane
The address register bits are used to translate the bits to make which of the following bit selections?
X and Y primary, secondary, and diode; stack; and inhibit upper and lower stack
Which selectors are activated only when writing zeros?
Inhibit
In a core read/write cycle, the read current is designed to change the state of the core(s) to (a) what value; and the write current is designed to change the state of the core(s) from (b) what value to (c) what value?
(a) Zero (b) zero (c) one
The process of reading cores to the zero state is known as which of the following types of readout?
Destructive readout
In a core memory, a restore cycle is necessary after data has been read from memory for what reason, if any?
To change the state of each selected core from zero to one
During a restore operation of zeros in a three-wire core, the absence of write current on which of the following lines will leave the cores in the zero state?
Digit
What specific number of paired film spots is used for each bit position?
Two
Current flow through which of the following lines will magnetize a film spot?
Word or sense/digit, depending on the function
In a film memory, a packet stores what specific number of bits of data?
2
Which, if any, of the following devices makes the mated film cells less susceptible to the disturbance from other cells in close proximity to them?
keeper (2nd film)
How is mated film memory structured?
Word organized
What item is the basic building block of the film memory stack?
packet (mated Film)
The memory capacity of a film core storage device is determined by which of the following factors?
Number of packets and the size of the array in the memory stack
In film storage, up to how many words can be selected at each memory location?
4
The address register bits used to translate the bits to make selections are processed in which of the following sequences?
Stack, memory location, and word at the address location
A mated film memory cell is read by which of the following methods?
A current is generated along the word line and a transverse field is applied to the thin film cell
What factor will determine the recorded state of the film?
The direction of the cell vector rotation induced film signal on the sense/digit line
When a one is to be stored, (a) what is the direction of the bit current in relationship to that used to store a zero and (b) what field steers the vector to the one state?
(a) Reversed (b) Longitudinal
In a restore operation of a film memory, what factor determines the direction of the digit current on the sense/digit line?
Binary value of the data register
Semiconductor memories are known by all of the following terms except which one?
Read-only memory (RAM)
Semiconductor memories have which of the following characteristics?
Non-destructive readout and volatile
Each RAM chip contains which of the following items?
Large numbers of memory cells and the logic to support them
The transistors used in flip-flops of static RAM may be MOS or bipolar. Compared to MOS, bipolar has what advantage, if any?
Higher access speed
In a static RAM, the address lines are used to enable the addressed memory cell flipflop circuit by row and column number.
true
Data is stored, or read from, the memory cells of SRAM via a total of how many lines?
4
The (a) address lines and the (b) I/O data lines are usually tied to what buses?
(A)Computer or memory system bus (B)Data bus
Each dynamic RAM cell consists of which of the following devices?
One MOS transistor and one tiny capacitor only
DRAM cells do not retain their charged state for more than a few milliseconds. This degradation is due to which of the following factors?
Time and temperature
To retain their charged state, DRAMs must be refreshed. Of the following methods, which one is (a) more cost effective because it uses what (b) device?
(A)External (B)Single refresh address generator
In DRAM organization, the data input and data output lines may be tied together in what type of application, if any?
One that uses a bidirectional data bus
Programs stored on ROM are often referred to as firmware for which of the following reasons?
They are more hardware than software
Compared to RAM, ROM has all of the same operational characteristics except which of the following?
Can be written to by normal computer accessing methods
ROM has what primary use?
Allows the computer to perform I/O operations
The acronym BIOS stands for what term?
Basic input/output system
The acronym NDRO stands for what term?
Non-destructive readout
In the example, the ROM chip memory array has a total of(a) how many decoders and (b) how many lines are input to these decoders?
(a) 2 (b) 13
ROMs may be made of which of the following materials?
Hardwired, magnetic, fusible links, and MOS and bipolar transistors
To perform ROM operations, which of the following circuits are used?
Timing, control signals, registers, flipflops, and internal buses
Compared to PROM, an erasable PROM has what additional advantage, if any?
It can be erased and reprogrammed