🚀 go-pugleaf

colas@modja.inria.fr (Colas Nahaboo) writes:

>My question is: what is the LEGAL way to know I am running on an ST with
>TOS 1.0 roms from a C program? [...]
>
>All I have seen is de-referencing the pointer
>	unsigned char *ROMS_YEAR = 0x00fc0018L + 3L;
>which gives you the year of the TOS (on US and French tos it is 0x86), but
>this is undocumented, and will surely break on the STe, since the Roms are
>not in the same place!

Good for you!  You're right, the ROMs are free to move from rev to rev.
So you can't use a constant for an address in the ROM.  However, you
can use a variable, and there is one: the system variable _sysbase
at $4f2 holds the base of "the OS header" which is where things like
the date are kept.

This code extracts the date as a LONG from the OS header, no matter where
it lives:

	char *sysbase = *(char **)0x4f2;
	long romdate = *(long *)(sysbase + 0x18);

romdate will have a number like 0x04061989 for April 6, 1989.

>PPPS: and do not tell me to pay to become a registred developper, all my atari
>programming is public domain! :-)

That doesn't matter.  If you paid to become a registered developer, you
would be able to look this stuff up instead of bothering all of us! :-)
You don't have to be a commercial developer to join the Atari developer
program.  (I know I'm answering your question anyway -- think of it as
advertising. (If you're a Net God, *don't* think of it as advertising!))

============================================
Opinions expressed above do not necessarily	-- Allan Pratt, Atari Corp.
reflect those of Atari Corp. or anyone else.	  ...ames!atari!apratt