programming is greek to me

[goflo at pacbell.net]

BossOz at aol.com wrote:
> Are we talking about software here? 

Yasu! A program consists of a series of instructions to the processor.
Each instruction is a unique combination of one's & zeros
known as an opcode. This combination is decoded by the processor and
the appropriate operation is performed. 

Since humans don't deal efficiently with long strings of 1's & 0's
the instructions are identified by acronyms called mnemonics - "POP A"
might signify "Take the value on top of the stack and load it into the
accumulator". Obviously "POP A" is more concise, and with a bit of
practice seems natural. 

Of course "POP A" means nothing to the uP (microprocessor) - It needs 
the appropriate opcode. 

Let's arbitrarily say an opcode of 11010001 results in the "POP A"
operation being performed. This is where an assembler comes in. An
assembler is a special kind of text editor which, when you type "POP A",
will output 11010001 to a file which can be read into the uP's program
memory.

A disassembler does the reverse, translating the contents of program
memory into mnemonics for examination.

The devil's in the details, of course.
Have fun!

Regards, Jack