Re: Prodos MLI difficulties

[dempson@swell.actrix.gen.nz (David Empson)]

[note: followups to comp.sys.apple2.programmer]

In article <88767@cup.portal.com> ScottM@cup.portal.com (Scott - Maxwell) writes:

> >Here is an example of what you might try:
> >
> >        dfb     $C0             ;   CREATE FILE
> >        da      creParm         ;   CREATE FILE PARAMETERS
> >        asc     '/THIS/IS/A/PAIN'
> >
> I have a question. I'm guessing that asc defines an ascii string. What do
> dfb and da do?

They are Merlin assembler directives.  DFB is "define byte", DA is
"define address".  DFB generates one byte of object code, containing
the operand.  DA generates two bytes of object code (in the usual low
byte first order), containing the operand.

By comparison, the ORCA/M assembler uses DC I1 and DC I2 for the same
operations.

Other assemblers might use DB and DW, or BYT and ADR, or something similar.

Note that Merlin's ASC command causes low-ASCII characters to be
output if you use single quotes (as in this case) and high-ASCII
characters if you use double quotes.


I see you have cut out part of the example.  The pathname here should
have a length byte first, and Merlin provides an STR directive
(string) which does this for you.
-- 
David Empson                                                               
dempson@swell.actrix.gen.nz                                                
Snail mail: P.O. Box 27-103, Wellington, New Zealand