[Coco] questions about constants

Wayne Campbell asa.rand at yahoo.com
Sat Sep 12 19:41:52 EDT 2009


I have looked at a dozen tutorials on assembly language programming. None of them address the op codes fcb, fcc or fcs, so I'm asking the assembly gurus on this list to help explain this to me.

What are the differences between fcb, fcc and fcs?
Is there a fci or fcr(/f/d) (for integer and real(/float/double) values)?

I know that:

  fcb = form constant byte   = any constant numeric byte value?
  fcc = form constant char   = any constant character that is displayable?
  fcs = form constant string = any constant string?

Are the following equivalent, so far as the assembler is concerned?

A. form constant byte:

  fcb   $20  
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $20 
  fcb   $42 B
  fcb   $41 A
  fcb   $53 S
  fcb   $49 I
  fcb   $43 C
  fcb   $30 0
  fcb   $39 9
  fcb   $0A  

B. form constant string:

  fcs   /            BASIC09/
  fcb   $0A

C. would using form constant char be equivalent?

  fcc   ' '  
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   ' ' 
  fcc   'B'
  fcc   'A'
  fcc   'S'
  fcc   'I'
  fcc   'C'
  fcc   '0'
  fcc   '9'
  fcb   $0A

Wayne



      



More information about the Coco mailing list