Path: utzoo!attcan!uunet!know!zaphod.mps.ohio-state.edu!julius.cs.uiuc.edu!psuvax1!rutgers!cbmvax!jesup From: jesup@cbmvax.commodore.com (Randell Jesup) Newsgroups: comp.sys.amiga.tech Subject: Re: PIPEs Message-ID: <15794@cbmvax.commodore.com> Date: 11 Nov 90 21:21:46 GMT References: <2424@wn1.sci.kun.nl> <6977@sugar.hackercorp.com> Reply-To: jesup@cbmvax.commodore.com (Randell Jesup) Organization: Commodore, West Chester, PA Lines: 40 In article ggk@tirith.UUCP (Gregory Kritsch) writes: >rhialto@cs.kun.nl (Olaf Seibert) writes: >>As I have been peeking though memory, it appears to be some Tripos >>convention that FileHandles may have some buffer attached to them. >>The argument line pointer that a CLI process receives simply points >>into this buffer. >So thats what the buffer variables are used for. Does anyone know where >they're interpreted - within Read() or the filesystem's ACTION_READ >code, or by some magical BCPL thing? By buffered I/O calls. These were BCPL-private in <= 1.3, and are public (and greatly extended) in 2.0. >>Of course, none of this is documented in the DOS manual. Nor should it >>be, in my opinion. But just for the curious, would it be possible that, >>when 2.0 has firmly settled, someone reveals the interesting details of >>the Tripos data structures? Only when it would be of no use to anyone to >>actually use the provided information? I'm afraid documenting more than we have to of private internals is liable to force us to allow people muck with them forever to retain compatibility. And, if as you say, it isn't of any use, what good does it do, except to encourage people to tie our hands? >There is a document on BCPL floating around. I had it two years ago, >but it was destroyed in a hard disk error (I think). It documents all >of the dos library, including the BCPL functions and how to call them. >From it, you can explain how some things work in AmigaDOS. That does show some of the internal BCPL global vector routines. However, programs calling them will NOT be supported forever, and NO ONE should write code to use them!!!! It costs us a fair bit of ROM and speed (and maintenance hassle) to support them for old BCPL programs, and at some point it may be dropped (though not soon). -- Randell Jesup, Keeper of AmigaDos, Commodore Engineering. {uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.cbm.commodore.com BIX: rjesup Common phrase heard at Amiga Devcon '89: "It's in there!"