[Coco] questions about constants

[Lothan]

Actually, not quite. With OS-9 assemblers

fcs /Basic09/
-or-
fcs "Basic09"

is equivalent to:

fcc 'B'
fcc 'a'
fcc 's'
fcc 'i'
fcc 'c'
fcc '0'
fcb '9' + 0x80

or equivalently

fcc "Basic0"
fcb '9' + 0x80

The differentiation is the fcb is for a single byte, fcc is for character 
data, and fcs is for strings in which the last character has the high-bit 
set. There is no fci, fcr, fcd with the assemblers that came with OS-9 or 
the Development System.

The delimiters don't really matter quite so much with fcc/fcs so you can use 
/, ', ", and perhaps a few others depending on your needs, but the delimiter 
at the start of the string must be the delimiter used to end the string.

--------------------------------------------------
From: "Wayne Campbell" <asa.rand at yahoo.com>
Sent: Saturday, September 12, 2009 7:41 PM
To: <coco at maltedmedia.com>
Subject: [Coco] questions about constants

> 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
>
>
>
>
>
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>