The EXT (external) modifier.

[boroko]

I was having trouble understanding the results that I was getting. I ran this to get a better view of how things were working. ...he can be taught...

INCLUDE "AllDigital.pbp"
DEFINE OSC 8          ' this was run on an 18F2525
OSCCON = %01110000
DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 24h ' Enable transmit, BRGH = 1
DEFINE HSER_CLROERR 1 ' Clear overflow automatically
DEFINE HSER_SPBRG 34  ' 57600 Baud @ 8MHz, -0.79%
SPBRGH = 0
BAUDCON.3 = 1         ' Enable 16 bit baudrate generator
ByteData    var byte[32] BANK0                                             
Arg         VAR WORD  EXT 
ArgWd0      var word
ArgHi0      var byte
ArgLo0      var byte
ArgWd1      var word
ArgHi1      var byte
ArgLo1      var byte
@Arg = _ByteData
hserout["ArgTest",10,13]
start:
CounterB    var byte
for CounterB = 0 to 31
ByteData[CounterB]= CounterB
next CounterB                                                                        

    hserout["Byte0= ",dec bytedata[0],", Byte1= ",dec bytedata[1],10,13]
    ArgWd0 = Arg[0]
    ArgHi0 = ArgWd0.highbyte
    ArgLo0 = ArgWd0.lowbyte
    hserout["Arg0 HiBtD= ",dec ArgHi0,10,13]
    hserout["Arg0 LoBtD= ",dec ArgLo0,10,13]
    hserout["Arg0 HiBtB= ",bin ArgHi0,10,13]
    hserout["Arg0 LoBtB= ",bin ArgLo0,10,13]
    hserout["Arg0 HiBtH= ",hex ArgHi0,10,13]
    hserout["Arg0 LoBtH= ",hex ArgLo0,10,13]
    hserout["Arg0= ",dec Arg[0],10,13]
    hserout["Byte2= ",dec bytedata[2],", Byte3= ",dec bytedata[3],10,13]
    hserout["Arg1= ",dec Arg[1],10,13]
    ArgWd1 = Arg[1]
    ArgHi1 = ArgWd1.highbyte
    ArgLo1 = ArgWd1.lowbyte
    hserout["Arg1 HiBtD= ",dec ArgHi1,10,13]
    hserout["Arg1 LoBtD= ",dec ArgLo1,10,13]
    hserout["Arg1 HiBtB= ",bin ArgHi1,10,13]
    hserout["Arg1 LoBtB= ",bin ArgLo1,10,13]
    hserout["Arg1 HiBtH= ",hex ArgHi1,10,13]
    hserout["Arg1 LoBtH= ",hex ArgLo1,10,13]
    hserout["Arg1= ",dec Arg[1],10,13]
   end

The results were:

ArgTest                                                                       
Byte0= 0, Byte1= 1                                                            
Arg0 HiBtD= 1                                                                
Arg0 LoBtD= 0                                                                 
Arg0 HiBtB= 1                                                                
Arg0 LoBtB= 0
Arg0 HiBtH= 1                                                                 
Arg0 LoBtH= 0                                                                 
Arg0= 256                                                                     
Byte2= 2, Byte3= 3                                                            
Arg1= 770                                                                     
Arg1 HiBtD= 3                                                                
Arg1 LoBtD= 2                                                                 
Arg1 HiBtB= 11                                                               
Arg1 LoBtB= 10                                                                
Arg1 HiBtH= 3                                                                 
Arg1 LoBtH= 2                                                                 
Arg1= 770

That let me see that it was being stored like this:
00000001 00000000 = 256
00000011 00000010 = 770
Don't know if that will help anyone, but it helped me understand a bit more.
Bo