Path: utzoo!utgpu!attcan!uunet!seismo!sundc!pitstop!sun!imagen!atari!apratt
From: apratt@atari.UUCP (Allan Pratt)
Newsgroups: comp.sys.atari.st
Subject: Re: bios function 0x7f
Message-ID: <1263@atari.UUCP>
Date: 15 Dec 88 21:48:36 GMT
References: <12076@hall.cray.com> <3767@druhi.ATT.COM>
Reply-To: apratt@atari.UUCP (Allan Pratt)
Organization: Atari (US) Corporation, Sunnyvale, California
Lines: 20

In article <3767@druhi.ATT.COM> dlm@druhi.ATT.COM (Dan Moore) writes:
> in article <12076@hall.cray.com>, rosenkra@hall.cray.com (Bill Rosenkranz) says:
> > after disassembling a code i found on some bbs which doubles the effective
> > on-screen travel of the mouse form, i found it ixecutes bios function 0x7F
> 
> 	There isn't a bios function 0x7f.  But it is a useful bios call
> if you intended to patch the bios handler on the ST.  When the ST bios
> or xbios handler receives an illegal function number it returns an error
> code and a pointer to the bios/xbios function pointer table.

Great! This is exactly the kind of "It works, so use it" philosophy
which makes it so hard to improve TOS in a backward-compatible way. 
Please do not rely on crap like this in your programs.  If you do, don't
expect them to work in the future.  Maybe I should make sure the hack
described above stops working, but I'm not vindictive or petty, so I
won't. 

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