assmeblers and disassemblers

[goflo at pacbell.net]

Bruce Plecan wrote:
> >For example.
> >LDA $FF
> >The above means "load the A register with value $FF (which is 255 to you
> and me).  The assember converts this to:
> >08FF
> >The microprocessor likes the latter, people prefer the former.  Hope that
> answered your question without making it more confusing.
 
> 08 would be an address, right?

Negatory. The hex value "08" is the instruction opcode. This is what
tells the
processor what to do, also called the "operator". The hex value "FF" is
called 
the operand, meaning that it used by the operator. Not all opcodes have
operands - Depends on the instruction.

> How do you know A=address 08?.

It does'nt. The particular instruction is specific to the A register.
Confusion factor may be that individual processor architectures may or
may not have register sets memory-mapped. Some do, some don't.
Additional
confusion available in "RISC" processors, like PIC's, which have
separate program and data memories.

Regards, Jack