Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!wuarchive!udel!haven!uvaarpa!murdoch!news From: mil@mendel.acc.Virginia.EDU (Maria I. Lasaga) Newsgroups: comp.sys.mac.programmer Subject: Re: More Help with ScrnBase, Please Message-ID: <1990Aug29.022048.674@murdoch.acc.Virginia.EDU> Date: 29 Aug 90 02:20:48 GMT Sender: news@murdoch.acc.Virginia.EDU Distribution: usa Organization: University of Virginia Lines: 132 In article <9954@goofy.Apple.COM> chewy@apple.com (Paul Snively) writes: > > In article <1990Aug27.170838.199@murdoch.acc.Virginia.EDU> > mil@mendel.acc.Virginia.EDU (Maria I. Lasaga) writes: > >> Any help would be greatly appreciated. I am very frustrated with this >> problem. I don't get why Apple doesn't put out a tech note on how to >> use the alternate video buffer on the "lower" macs. > > That's easy. The Tech Notes are basically concerned with correcting > errors in Inside Macintosh, with documenting new features as they come out > (rather than waiting for a new Inside Macintosh), and for addressing > misunderstandings, especially when they lead to software incompatibilities > across the various machines/system software combinations. > There are tech notes that amplify information that is available in Inside Macintosh, such as how to optimize copybits. I don't think that information that amplifies how to use the alternate screen buffer would be inappropriate. There is only one reference as to how to do so in IMIII-20. Please don't get the wrong idea. I think the IM volumes are great. This happens to be one problem I have had for which I have found very little documentation anywhere. > Since the primary application of the alternate screen buffer is for games, > it just hasn't gotten that high a priority for us, even though it is > definitely a source of confusion and compatibility problems (for example, > you can't just point the screen to the alternate screen buffer; you also > have to set a bit on the VIA). > I disagree that the primary application of the alternate screen buffer is for games. There are many scientific applications that require rapid displays of images. In fact, there are several articles available in academic journals that describe ways to optimize how quickly a bit-mapped image is displayed on a Mac screen. Unfortunately, we are dealing with complex images and need to use an alternate screen buffer. This is a very common operation used by many of my colleagues nationwide who use IBM PC's in their research. I happen to prefer the Macintosh system. I know of at least some other colleagues who use Macs who could use some illumination on how to switch between a main and an alternate screen buffer of a Mac. I don't think I am alone in academia. > However, the alternate screen buffer, along with code to utilize it, is > presented very well in one of MacTutor Magazine's anthologies of back > issues. The article is by Mike Morton, and I highly recommend it. > Great. Can I bother you for the date of the article? I don't subscribe to MacTutor, and will need to borrow a copy. >> Granted, the Mac II's >> don't have an alternate buffer, but not everyone is into software > development >> for use on all machines. > > Very true, but our job is basically to support Apple Partners who, for the > most part, _do_ do development for use on all Macintoshes. Of course, the > academic environment (among others) is different, and we're trying to find > ways to effectively address that. (There are only about 35 or so of us > and about 7,000-8,000 partners.) > That would be great if a little more emphasis would be placed on assisting software development in the academic environment. I think there might be more individuals who would switch from IBM PC's to macs in the academic world if more support were provided. I could be wrong. >> Why not allow us to develop some >> software that doesn't run on the Mac II? > > No one is stopping you; rather, by pointing you to a source of the > information, I am trying to help you. However, I must admit that I find > your railing about _us_ not being the source of the information vexing. > My frustration comes from trying to request help several times on the network, from buying numerous books that supposedly might help, etc., but not really getting anywhere. I am not a computer scientist or engineer by training, so that is probably a large part of the problem. It just seems to me that the ability to use an alternate screen buffer is a good capability that should be better documented. However, it seems from your message that few individuals other than myself or those that develop games for the mac have any use for the alternate screen buffer. So perhaps I shouldn't be complaining about the lack of documentation. >> I myself purchased an SE because it >> had an alternate slot to which I could attach an external monitor, and >> because it had an alternate video buffer. I need to use these two options >> for research purposes. Yet I can't find documentation anywhere that tells >> me how to take advantage of either of these two options!! > > It's true that the sum total of information about Macintosh programming is > scattered all over. We're working on ways to consolidate it. The > Developer CD is a good example--IM I-V, the Tech Notes, sample code, etc. > all in one place. It's worth the price of the CD-ROM drive, in my opinion. > Again, please don't get me wrong. I think that Apple does a very good job of providing support for software developers, and this in spite of the many changes in Macintosh hardware over the years. I happen to think that there is an important though maybe small void in the documentation that merits filling: how to use the alternate screen buffer of earlier macs. > > __________________________________________________________________________ > Paul Snively > Macintosh Developer Technical Support > Apple Computer, Inc. > > chewy@apple.com > > Just because I work for Apple Computer, Inc. doesn't mean that I believe > what they believe, or vice-versa. > __________________________________________________________________________ > > ------------------------------------------------------------------------- Maria I. Lasaga Dept. of Psychology Gilmer Hall University of Virginia Charlottesville, Virginia 22903 mil@virginia.bitnet -------------------------------------------------------------------------