anson@spray.CalComp.COM (Ed Anson) (08/26/88)
In article <16109@apple.Apple.COM> casseres@apple.com.UUCP (David Casseres) writes: > >Actually, the OS doesn't do anything in particular for device-independent >printing. The part of the Printing Manager that's in the system is just >a little bit of glue that knows how to pass Printing Manager calls to the >current printer driver. If it's really that simple, why does Apple choose not to document that interface? 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. The results of Apple's current policy are as follows: 1. Our customers want our printers on their Macintoshes. We will support them. 2. Apple doesn't provide adequate information, so we have to find other sources. Those sources are necessarily incomplete and/or inaccurate. 3. Our printer drivers will inevitably violate some unstated Apple standards in the area, and will break. Apple will blame us for not following their rules. As I pointed out in a previous posting, Apple *has* promised to support printer developers at some unspecified time in the future. I think the current lack of support is not so much a matter of long term policy, as it is a short term reaction to Apple's acknowledged shortage of Tech Support staff. That is, they can't cope with printer driver developers right now. (The opinions stated above are my own. Please don't blame my employer!) -- ===================================================================== Ed Anson, Calcomp Display Products Division, Hudson NH 03051 (603) 885-8712, anson@elrond.CalComp.COM
casseres@Apple.COM (David Casseres) (08/30/88)
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
earleh@eleazar.dartmouth.edu (Earle R. Horton) (08/30/88)
In article <16289@apple.Apple.COM> casseres@apple.com.UUCP (David Casseres) writes: >... 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. > Fine, I'll put in my resume that I know all about Apple Computer Company folklore. That should get me a job real quick. People are suspicious of this interface precisely because it is not documented. (It was once.) The feeling is that Apple can, at any moment, release the System Tools that will make ALL third party printer drivers go belly up. We don't know how or why you would choose to do this, but we know you can, and that is not a real good feeling to have if you want to market a product that depends on this interface. >...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. What are you people planning on doing? I am just dying to know! How much can the System change, and this box in front of me still be considered a Macintosh? I think we need another Compatibility Technote, and real soon! Earle R. Horton. 23 Fletcher Circle, Hanover, NH 03755 (603) 643-4109 Email address expires soon, but try my wife: maxine@eleazar.dartmouth.edu.