What is a Computer? A computer is an electronic machine that can be programmed to accept data (input), process it into useful information (output), and store it in a storage device for future use
Characteristics of a Computer • It’s a machine. • It is electronic. • It is automatic. • It can manipulate data. • It has memory • It has logical function
Capabilities of a Computer • Speed • Accuracy • Repetitiveness • Storage • Programmable
Limitations of a Computer • Cannot operate without a set of instructions. • Cannot derive from objects. • Can detect errors but cannot correct them. • Computer are subjects to occasional breakdowns. • Cannot run without electric power. •
CLASSIFICATION OF COMPUTERS
ACCORDING TO PURPOSE
(General and Specific)
General-purpose computers- capable of dealing with a variety of different problems.
Special-purpose computers - designed to perform specific task, with limited capabilities, and the program of instructions is built into the machine
ACCORDING TO DATA HANDLED
(Analog, Digital, Hybrid)
Analog computer – used for scientific, engineering and process-control purposes-operations that result to approximate values.
Digital computer – used for business applications, and also scientific operations, and are ideal when 100% accuracy is desired, thus resulting to data that are exact in values.
ACCORDING CAPACITY
(Microcomputers, Minicomputers, Mainframes, & Supercomputers)
Microcomputers - Small computers which are portable that use microprocessor. Ex: Desktops, Laptop, Notebooks, PocketPC and Pen Computers
Minicomputers
- Machines, which are in the middle of microcomputers and mainframes in terms of cost and capability. These acts as “servers” w/c are connected to several workstations or terminals.
Mainframes
- The oldest category, these are air-cooled computers bigger in sizes. Used mostly