Path: utzoo!attcan!uunet!unisoft!bdt!david From: david@bdt.UUCP (David Beckemeyer) Newsgroups: comp.sys.atari.st Subject: Re: bios function 0x7f Message-ID: <465@bdt.UUCP> Date: 22 Dec 88 06:36:09 GMT References: <12076@hall.cray.com> <3767@druhi.ATT.COM> <1263@atari.UUCP> Reply-To: david@bdt.UUCP (David Beckemeyer) Organization: Beckemeyer Development Tools, Oakland, CA Lines: 33 In article <1263@atari.UUCP> apratt@atari.UUCP (Allan Pratt) writes: >In article <3767@druhi.ATT.COM> dlm@druhi.ATT.COM (Dan Moore) writes: >> 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... I know Dan pretty well and I like him, but in this case I have to agree with Allan Pratt. The reason I'm posting a followup though is becuase this sort of "philosophy", as Allan calls it, also is part of the reason why "clean" BIOS trap handlers are dificult to implement too. In order to be compatible with these types of programs, the trap handler must implement all the documented functions as well as the undocumented "features" too. There are safe and legal ways to intercept BIOS traps that are TOS/ROM independent. So why do some people cheat? Sometimes the "legal" ways aren't as fast or as compact as the "cheating" ways, so programmers can be lured into these practices. Often the pressure comes from the Users who want it FAST FAST FAST and TINY TINY TINY. Then when the next TOS ROMS come out, everybody's bitching becuase their nifty programs don't work anymore. But in the long run breaking the rules is bad for everyone, and limits the potential for future success of the very machine we all love so much. -- David Beckemeyer (david@bdt.UUCP) | "Lester Moore - Four slugs from a .44 Beckemeyer Development Tools | no Les, no more." 478 Santa Clara Ave. Oakland, CA 94610 | - Headstone at Boot Hill UUCP: {uunet,ucbvax}!unisoft!bdt!david | Tombstone, AZ