Vocabulary:

1) Random-access memory - strictly a computer memory, structured, so that the time required to access any data item stored in the memory is the same as for any other item. Now more often used to describe a semiconductor memory that can be used for reading and writing data.

2) Cathode-ray-tube - a device used to generate pictures as found in a television or visual display.

3) Control unit - the part of the computer which directs the sequence of operations, interprets the instructions, and provides the requisite signals to execute those instructions.

4) Arithmetic and logic unit - a device which executes arithmetic and/or logic operations according to the instructions in a program.

5) Accumulator - a register in which numbers are totaled, manipulated, or temporarily stored for transfers to and from memory or external devices.

6) Address - a unique label, name, or number that identifies a memory location or a device register for access by a computer. To send an address to a memory or a device in order that a particular location in memory or the device may be identified.

7) Fetch - the action of reading data or instructions from memory.

1. Give the Russian equivalents to the following:

silicon chip, microprocessor chip, modular chips, multi-chip arrangement, arithmetic and logic unit, central processing unit, a cathode-ray-tube display, a two-dimensional plotter, address buffer, a bit-sliced organization, strings of binary digits, interface, program memory, random-access memory

2. Give the abbreviations of the following:

large-scale integrated circuits, random-access memory, input-output, central processing unit, arithmetic and logic unit

3. Give the English equivalents to the following:

процессор, кристалл, синхронизация, адресный буфер, входной/выходной сигнал, собирать по одной плате, хранить данные, двоичный знак, логические и арифметические операции.

Text 3.6 Classification of Microprocessors

Pre-Reading Task:

1. Read the text “Classification of Microprocessors”.

2. Study the definition of terms given below the text.

3. Discuss the following questions in group:

4. How are modern microprocessors classified?

5. What are the levels in hardware classification?

6. What are the characteristic features of the second level of the microprocessors' classification?

7. What are the advantages of the small computer system level?

8. What is the FDS intended for?

The flood of microprocessors and microcomputers reaching the market, combined with the rapid rate of innovation, guarantees that any attempt to catalogue them will be instantly obsolete. A more fruitful introduction to the "micro" marketplace is to classify systems hierarchically according to their capability and function. Along these two dimensions there is a well-defined upward progression in both hardware¹ and software. In hardware the levels are chips, modules², "breadboard" systems, small computer systems, full-development systems and multiprocessor systems. This hierarchy is not absolute because the evolving technology creates ever more powerful chips, some of which can bridge two or three hierarchic levels. Chips are used to construct a module, modules to construct a small computer system (SCS) and small computers to construct a full-development system (FDS). Multiprocessor systems can incorporate modules, SCS's or FDS's, depending on the application and complexity.

At the first level of the hierarchy are the microprocessor chips, representing the large-scale integration of tens of thousands of individual electronic devices: transistors, diodes, resistors and capacitors. At this level there are also more specialized chips: random-access memories (RAM's), read-only memories (ROM's)³, programmable read-only memories (PROM's), input-output (I/O) interfaces and others. The cutting edge of the technology works most directly at the chip level, providing, for example, RAM's of ever-higher storage capacity⁴.

Generally the various kinds of chips are grouped into families that are compatible with particular microprocessors. The families will include a series of RAM, ROM and PROM chips to create a memory system, a series of interface chips capable of handling both parallel and serial input-output functions and miscellaneous chips to enhance system capabilities, such as high-speed arithmetic operations. Master-control chips are needed to establish priorities⁵ and to keep signals flowing smoothly through the complex maze of interconnections. The compatibility of chips and chip families made by different manufacturers varies widely.