Ibm Personal Computers.
In 1979 the IBM has decided to try to create a small PC on the basis of the microprocessor.
Two main principles which have given the success of these computers were used .
1. Open architecture.
The sense of this principle is that the computer formed by the not monolithic block, but like the meccano.
All basic units were built as independent devices and connected through universal plugs (bus). A connecting circuit and the rules of assembly were not protected, and were accessible to all users.
The given principle has allowed not only to build and to upgrade the computer to any user, but also has enabled other computer corporations to develop devices for a IBM PC copying the original and developing the cards. It has resulted in growth of a competition, lowering of computers cost and appearance of the real standard for peripheral units "IBM-compatible". The IBM has lost monopoly of the computers, but its computers have received unprecedented popularity.
2. Support " from below upwards ".
The appearance of new modifications of IBM PC should support compatibility with all "old" developments. At a level hardware and software.
This principle guaranteed to the developers of computers, that the devices and programs, developed by them, "will not become outdated" with appearance of more powerful IBM PCs in future.
In that time the IBM has concluded the contract with the small corporation «Microsoft» for the creation of software for IBM PC. This corporation has to observe both principles too.
In 1981 the first PC of IBM was issued on the basis of the processor Intel-8080.
To this time the cost of creation of programs for the computer was more expensive then the cost of the computer.
Before appearance of IBM PC the programmers were forced with appearance of the new computer to create programs for it anew. It was too long and too expensive.
Therefore with appearance of IBM PC this standard has become main for manufacturers of the software, since it supports their "old" developments. The corporation of Microsoft designed only the basic software (operating system), and other programs were installed on IBM PC only through an operating system.
The Microsoft has saved this given monopoly till now.
It has provided unprecedented financial success.
The diagram of ibm pc Hardware
CPU |
Co-Processor |
Local BUS |
Data BUS |
Address BUS |
Max RAM |
Frequency, MHz |
RAM |
HDD |
Cash external |
Cash I |
Cash II |
Monitor |
Peripherals |
Software |
8080/8086 (XT) |
NO |
8 |
16 |
20 |
1 Mb |
8…12 |
512 Kb |
NO |
NO |
NO |
NO |
CGA |
Printer, mouse |
DOS |
80286 (AT) |
80287 |
16 |
16 |
24 |
16 Mb |
12…25 |
1024 Kb |
40…80 Mb |
YES |
NO |
NO |
EGA, VGA |
+Scanner, modem |
DOS |
80386DX |
80387DX |
32 |
32 |
32 |
4 Gb |
25…40 |
4…16 Mb |
120 … 850 Mb |
YES |
YES |
NO |
VGA, sVGA |
+CDROM, SB |
DOS, Win 3.1, 3.11 |
80386SX |
80387SX |
32 |
16* |
24 |
16 Mb |
25…33 |
2…8 Mb |
80 … 250 Mb |
YES |
NO |
NO |
VGA, sVGA |
+CDROM, SB |
DOS, Win 3.1, 3.11 |
80486SX |
NO |
32 |
32 |
32 |
4 Gb |
33…80** |
4…32 Mb |
420 … 850 Mb |
YES |
YES |
NO |
VGA, sVGA |
All kinds |
DOS, Win 3.1, 3.11 |
80486DX |
Built-in |
32 |
32 |
32 |
4 Gb |
66…133** |
4…64 Mb |
640 Mb… 2,5 Gb |
YES |
YES |
NO |
VGA, sVGA |
All kinds |
DOS, Win 3.1, 3.11 Windows95 |
Pentium I |
Built-in |
32 |
64 |
36 |
64 Gb |
75… 300** |
8…128 Mb |
850 Mb… 4,5 Gb |
YES |
YES |
NO |
sVGA |
All kinds |
Windows95,98 |
Pentium II |
Built-in |
32 |
64 |
36 |
64 Gb |
300… 450** |
32…128 Mb |
4 Gb … 20 Gb |
YES |
YES |
YES |
sVGA |
All kinds |
Windows 95,98,NT |
Celeron |
Built-in |
32 |
64 |
36 |
64 Gb |
300… 800** |
32…256 Mb |
4 Gb … 40 Gb |
YES |
YES |
Small |
sVGA |
All kinds |
Windows 95,98,NT |
Pentium III |
Built-in |
32 |
64 |
36 |
64 Gb |
450…1000** |
64…512 Mb |
30 Gb … 80 Gb |
YES |
YES |
YES |
sVGA |
All kinds |
Windows 95,98,NT Windows2000 |
Pentium IV |
Built-in |
32 |
64 |
36 |
64 Gb |
1000…3500** |
128Mb…2 Gb |
40 Gb … 300 Gb |
YES |
YES |
YES |
sVGA |
All kinds |
Windows 95,98,NT Windows XP |
* – This CPU can use 32-bit commands with 2 time
** – CPU works with multiply frequency
The diagram of IBM PC development.
The diagram of shorthand notation for IBM PC.
The diagram of HDD for IBM PC.
The diagram of prices of IBM PC.
The motherboard. The interface connections. Chipset.
RAM. The Processors (CPUs). Socket.
