Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!apple!casseres
From: casseres@Apple.COM (David Casseres)
Newsgroups: comp.sys.mac
Subject: Re: Printer Support (was Re: Microsoft cuts corners, actuall)
Message-ID: <16289@apple.Apple.COM>
Date: 29 Aug 88 22:06:49 GMT
References: <870217@hpcilzb.HP.COM> <76000279@p.cs.uiuc.edu> <16109@apple.Apple.COM> <2419@spray.CalComp.COM>
Reply-To: casseres@apple.com.UUCP (David Casseres)
Organization: Apple Computer Inc, Cupertino, CA
Lines: 35

In article <2419@spray.CalComp.COM> anson@spray.UUCP (Ed Anson) writes:

>Those of us who are asking Apple for some help, are not asking for info or
>advice on programming our printers. We know how to do that! All we ask is a
>good description of the Printing Manager interface.

I guess I'm not sure what you mean by the Printing Manager interface.  The
part that's in the system really does nothing except pass an application's
call, such as PrOpenDoc, to the current printer driver by loading and locking
one of the PDEF resources of that driver and jumping into a jump table at the
beginning of that resource.  Apple doesn't document that at present but it's
rather well known in the folklore; anyone who has any kind of driver going
knows all there is to know about that interface.

The trouble is that knowing that much doesn't really get you anywhere, as you
undoubtedly know if you're in the printer driver game.  Now, if what you
mean by the Printing Manager interface is exactly what PrOpenDoc and all the
other calls should _do_, the answer is that that is NOT simple or easy to
document.  The details differ for each and every printer driver done to
date, and the exact way to implement one of those calls for a new driver
is often something that needs to be negotiated by the developer with the
developers of the other drivers, and the MultiFinder people, and the Print-
Monitor people, and the Toolbox people, and even the people working on the
next two or three operating systems for future CPUs.

I think what people really want is for Apple to define a subset of the
Apple printing model for third parties; one that can be supported in a
general way and that Apple can promise to support for the foreseeable future,
without giving away the store, and that is general enough for all sorts of
printers that haven't been invented yet.  It's kind of a tall order...

And I don't mind saying once again that I don't speak for Apple or even for
the printing group, or make any policies, or anything.

David Casseres