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From: phillip@cbmvax.cbm.UUCP (Phillip Lindsay)
Newsgroups: net.micro.amiga
Subject: Re: Re: Some remarks to AmigaDos.
Message-ID: <943@cbmvax.cbmvax.cbm.UUCP>
Date: Wed, 29-Oct-86 14:31:05 EST
Article-I.D.: cbmvax.943
Posted: Wed Oct 29 14:31:05 1986
Date-Received: Wed, 29-Oct-86 22:21:37 EST
References: <545@husc6.HARVARD.EDU>
Organization: Commodore Technology, West Chester, PA
Lines: 51

> Summary: There is one use for BCPL on the Amiga
> 
> In <148600179@uiucuxc> Wayne Hamilton writes:
>>    now that i've said all that, you can probably just forget most of it.
>>BCPL doesn't provide any compelling advantage over C and assembler, so
>>there's not much reason to want to write programs with it.  buying the
>>book might be a good idea, if you're interested in hacking on the internals
>>of AmigaDos.
> 
> 	Yes, if you want to write an AmigaDOS device driver (not
> just an Exec device but an AmigaDOS device) you have to write the
> interface code in either BCPL or Assembler that looks like BCPL.
> Either way you have to learn about BCPL and its calling conventions,
> etc.  So, for example, if someone wanted to write an AmigaDOS device
> driver for the clipboard.device (HINT HINT) you would need to write
> the glue code in BCPL so you could access it through the filesystem
> (i.e., as in fopen("CLP:","r");) in the same manner as a regular file.
> This, of course, is a VERY useful thing to do, since almost all programs
> access files and so on through AmigaDOS devices rather than directly
> through Exec.  (It is unfortunate that we have two levels of devices,
> and that you cannot write AmigaDOS drivers in a completely compatible
> fashion in C.  This is the design legacy of Tripos.)
> 
> 				-Mitsu
> 
> 
> 	wayne hamilton
> 	U of Il and US Army Corps of Engineers CERL
> UUCP:	{ihnp4,pur-ee,convex}!uiucdcs!uiucuxc!hamilton
> ARPA:	hamilton%uiucuxc@a.cs.uiuc.edu	USMail:	Box 476, Urbana, IL 61801
> CSNET:	hamilton%uiucuxc@uiuc.csnet	Phone:	(217)333-8703
> CIS:    [73047,544]			PLink: w hamilton

I think you better look at an earlier posting I made "my-handler". A
AmigaDos handler written *totally* in C. Under release 1.2 you can specify
a GlobVec of -1 in the device node and when AmigaDos loads (creates) you he
won't try and start you up like a BCPL program... BTW, the initial packet is 
sent to you...you don't find it in D1. (if your GlobVec == -1 ) 

-phil

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