secound generation language

Assembly or assembler language was the second generation of computer language. By the late 1950s, this language had become popular. Assembly language consists of letters of the alphabet. This makes programming much easier than trying to program a series of zeros and ones. As an added programming assist, assembly language makes use of mnemonics, or memory aids, which are easier for the human programmer to recall than are numerical codes.

Second-generation language arose because of the programming efforts of Grace Hopper, an American computer scientist and Naval officer. Hopper developed FLOW-MATIC, a language that made programming easier for the naval researchers using the ENIAC computer in the 1940s. FLOW-MATIC used an English-based language, rather than the on-off switch language the computer understood. FLOW-MATIC was one of the first "high-level" computer languages. A high-level computer language is one that is easier for humans to use but which can still be translated by another program (called a compiler) into language a computer can interpret and act on.

first generation computer language

A computer language is the means by which instructions and data are transmitted to computers. Put another way, computer languages are the interface between a computer and a human being. There are various computer languages, each with differing complexities. For example, the information that is understandable to a computer is expressed as zeros and ones (i.e., binary language). However, binary language is incomprehensible to humans. Computer scientists find it far more efficient to communicate with computers in a higher level language.



A first-generation programming language is a machine-level programming language.

Originally, no translator was used to compile or assemble the first-generation language. The first-generation programming instructions were entered through the front panel switches of the computer system.

The main benefit of programming in a first-generation programming language is that the code a user writes can run very fast and efficiently, since it is directly executed by the CPU. However, machine language is a lot more difficult to learn than higher generational programming languages, and it is far more difficult to edit if errors occur. In addition, if instructions need to be added into memory at some location, then all the instructions after the insertion point need to be moved down to make room in memory to accommodate the new instructions. Doing so on a front panel with switches can be very difficult. Furthermore, portability is significantly reduced - in order to transfer code to a different computer it needs to be completely rewritten since the machine language for one computer could be significantly different from another computer. Architectural considerations make portability difficult too. For example, the number of registers on one CPU architecture could differ from those of another.

Difference between l1,l2,l3

what is cache?
A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations. As long as most memory accesses are cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory.
When the processor needs to read from or write to a location in main memory, it first checks whether a copy of that data is in the cache. If so, the processor immediately reads from or writes to the cache, which is much faster than reading from or writing to main memory.
The diagram on the right shows two memories. Each location in each memory has a datum (a cache line), which in different designs ranges in size from 8[1] to 512[2] bytes. The size of the cache line is usually larger than the size of the usual access requested by a CPU instruction, which ranges from 1 to 16 bytes. Each location in each memory also has an index, which is a unique number used to refer to that location. The index for a location in main memory is called an address. Each location in the cache has a tag that contains the index of the datum in main memory that has been cached. In a CPU's data cache these entries are called cache lines or cache blocks.
Most modern desktop and server CPUs have at least three independent caches: an instruction cache to speed up executable instruction fetch, a data cache to speed up data fetch and store, and a translation lookaside buffer used to speed up virtual-to-physical address translation for both executable instructions and data.

what is l1,l2,l3
L1 cache is physically next to the processing core and is implemented in SRAM, or Static RAM which is fast and constant when powered on. It does not require refresh cycles. It is generally split with half used for instruction code and the the other used for data.
L2 cache is physically close to the core, but is implemented in DRAM or Dynamic RAM and goes through refresh cycles many time a second to retain its memory. It is not as fast as L1 and cannot be accessed during refresh.
L3 cache has come into vogue with the advent of multi-core CPUs. Whereas these chips will have both L1 and L2 caches for each separate core; there is a common fairly large L3 shared by all cores. It is usually the size of all other caches combined or a few multiples of all other caches combined. It is also implemented in DRAM. One unusual thing is that a multi-core chip that is running software that may not be capable of or need all cores will have a core flush its caches into the L3 before that core goes dormant