Path: utzoo!mnetor!uunet!mcvax!ukc!its63b!hwcs!neil
From: neil@cs.hw.ac.uk (Neil Forsyth)
Newsgroups: comp.sys.atari.st
Subject: System vars, Linking
Message-ID: <1727@brahma.cs.hw.ac.uk>
Date: 3 Mar 88 10:10:48 GMT
Organization: Computer Science, Heriot-Watt U., Scotland
Lines: 56
Keywords: Undocumented, Clumsy


We recently got Landon Dyers MADMAC assembler for the ST and with it is a
file of definitions (atari.s), a portion of which is shown below:- (risky?)

_sysbase	=	$4f2	; -> base of OS
_shell_p	=	$4f6	; -> global shell info
end_os		=	$4fa	; -> end of OS memory usage
exec_os		=	$4fe	; -> address of shell to exec on startup
scr_dump	=	$502	; -> screen dump code
prv_lsto	=	$506	; -> _lstostat()
prv_lst		=	$50a	; -> _lstout()
prv_auxo	=	$50e	; -> _auxostat()
prv_aux		=	$512	; -> _auxout()

Question 1: Are the last five entries officially supported?
   "     2: If so can we have some clear documention please?
(some seem fairly obvious but "Give us News before we abuse" :-)

These variables don't exist in the Bios Listing (Rev A) that came with the
dev-kit and lie in "No mans land" , but if Landon put them in a file for
distribution ...

Another issue:

If the Developers Kit is now being shipped with the Mark Williams C Compiler
instead of the Alcyon C Compiler where do we now stand with respect to link
formats? ALCYON C,AS68,LINK68,MADMAC & ALN use DRI/CPM68K object file formats
but MWC use their own (as does MEGAMAX, METACOMCO/GST etc grrr!). 

MWC does comes with an assembler (with pretty some stange syntax eg. a $ not a 
# for immediate) and a utility to convert DRI to MW link format (one way
arrogance :-). To make a composite program with this mess one would have to:

 Assemble with MADMAC
 do a Partial link with ALN (I like the -i option)
 Convert DRI to MWC object file (Assuming of course DRTOMW.PRG likes ALN)
 Compile the C and link the final beast with MWC

to be able to get the full benefit from MADMAC,ALN & MWC.
Imagine trying this with a ram disk instead of a hard disk. :-(

And speaking of ram disks: If you know anything please help Mr. Franco 
to fix ETERNAL2 to work with the new roms.

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 Neil Forsyth                           JANET:  neil@uk.ac.hw.cs
 Dept. of Computer Science              ARPA:   neil@cs.hw.ac.uk
 Heriot-Watt University                 UUCP:   ..!ukc!cs.hw.ac.uk!neil
 Edinburgh
 Scotland
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