Back again for help in understanding a few more items.

1.  Recently I cut and pasted a snippet of code that contained a "bnz" 
instruction.  I massaged the code to read and move EEPROM data values 
that I defined using "de" directives into data memory area (unused 
general special registers).  I used MPLAB SIM to execute the resultant 
hex code and all went well.  However, when re-reading the code I noticed 
the "bnz" instruction and it dawned on me I had never actually seen that 
instruction in the list of mid-range instructions I was reading ... a 
separate .pdf document.  The instruction hadn't rang any  ding dong 
bells on first perusal as I have used instructions like that in other 
assembly languages.  So I first took a look at the Help file in MPLAB 
IDE and sure enough it was listed ... but as a Special Instruction 
Mnemonic.  I saw a few other such mnemonics and thought "this is 
great".  Then upon further reading and investigation at other sources, I 
came to the conclusion that it was greatly discouraged to use these 
mnemonics. I guess I could refer to them as legacy mnemonics or as sort 
of mini-macros for lack of a better term.  I sure miss those 
instructions types like bz, bnz, etc. LOL!

I'll stay away from using them, but wondered why were they developed in 
the first place?  Any historical comments welcomed.


2.  I read in MPLAB IDE document and other sources that one should use 
an org directive of ORG H'2100 when defining starting EEPROM data memory 
location for most MID-Range PIC's.  I never read anything that stated 
why one must use this particular defined location.  It seemed to me then 
that this is somewhat MPLAB IDE specific so I hunted around the MPLAB's 
.lkr files and saw where for all of the mid-range PIC devices that I 
looked at had a start address of 0x2100.  The following is an excerpt of 
the 12f683_g.lkr file.

CODEPAGE   NAME=eedata     START=0x2100   END=0x21FF   PROTECTED

Not sure what it all means and I should note the END value in other .lkr 
files did not necessarily correspond to the above listed value:  
END=0x21FF.  I am aware the different PIC microcontroller chips have 
different EEPROM sizes.

Can I conclude that the org directive (ORG H'2100) I listed above is 
simply a requirement to supply a predefined PIC device's parameter to 
the MPLAB linker?  To me, it would appear so, but am asking confirmation.

Sorry if I'm too wordy ... I just hope I'm using the correct words to 
ask my questions.

Thanks in advance,

Bo
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