|The word BUS stands
for Bidirectional Uniting System.
A BUS "only" a collection of
parallel wires or tracks which holds a digital value 0/1 or they
could be undefined (not driven)
The last state called Z or the high impedance state
More elements which present in
collection of simple commands which the CPU "born" with
- Transfer instructions for
moving data between registers and the I/O
- Arithmetic instructions for
addition, subtraction, multiplication and division
- Logic instructions like AND,
OR, NOT, COM and XOR handy as well.
- Branch and Jump instructions
makes it possible for a program to make decisions
- The internal CPU control
also needed for a programmer.
of memory and IO:
makes it possible to access a specific memorycell
made for loading constants into registers
indirect makes it possible to perform calculation
at a address at runtime
for moving data between registers.
/ Output for reaching the IO-Space
first version for PCs was DOS, CP/M-86, OS2
- Now the most popular Windows
- A OS enable the user to
start and stop programs
- The OS performs multitasking
(more the one program running at the same time)
- Manage the file-system.
- Enables net-working.
of PC uses doesn't have worries about the internal of their
PC's such as hardware structure and assembler programming.
(The same true for car-owners - they just hit the road)
- Word processing, Browsers
and Games popular applications.
- With a compiler for high
level languages like: C, C++ C#, Java, Delphi, Visual Basic
and so on .. will it be possible to write programs for a PC
without detailed knowledge of the internal. (Link
to timeline )
by nature "general purpose"
- Its possible to buy PC's for
- Special applications
programs for PC's makes them act like PLC's (Search for more
information about SoftPLCs yourself)
- Programming of a PC not and
easy task if you must work with the hardware in order to get