ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University) (10/31/90)
The DeskTop Manager is Apple's new way of keeping track of some of the information that the Finder needs to know about a volume-- where the applications are, what their creator codes are (so the Finder knows which one to launch when you double-click on a document), and what icons to display for which files. The old way of doing this is the invisible "Desktop" file that you will find on all your floppies. "Desktop" is a resource file, managed by using Resource Manager calls. This has a couple of disadvantages: * the Resource Manager is slow when dealing with lots of resources * there is a limit on how many resources you're allowed to have in a single file. The Desktop Manager replaces the "Desktop" file with two new invisible files called "Desktop DB" and "Desktop DF". These are not resource files, so they are not subject to the limitations of the Resource Manager mentioned above. Also, the Desktop Manager code is callable as a set of system services, rather than being built into the Finder. The advantage with this is that other programs can take advantages of the Desktop Manager's services, without having to know the formats of the desktop database files themselves. This is particularly useful under MultiFinder, when you can't open those old Desktop files anyway, because the Finder has them locked. Under System 6.0.x, the Desktop Manager is implemented as a separate INIT that you need to have in your System Folder at startup time. As far as I know, Apple's only officially-supported use of this file is on an AppleShare server: if you install it under any other circumstances, you do so at your own risk. But it becomes an integral (hence, supported) part of the system with version 7.0. What's the disadvantage of using the Desktop Manager? In a word, compatibility. To minimize this problem as far as possible, the Desktop Manager will not create its database files on a volume 1.4Mb in size or smaller (i e all current standard floppy disk formats)--this forces the Finder to keep on using the old-style Desktop file on those volumes. That way, you can continue to exchange floppy disks with people who don't use the Desktop Manager, without any odd things happening. However, the first time you install the Desktop Manager on your hard disk and restart, you may find that all your documents revert to the plain, generic-looking icons. And double-clicking on any of them will produce the "Application is busy or missing" message. This is because the Finder has suddenly stopped looking at the Desktop file on the hard disk, but there is initially no information in the new Desktop Manager database for it to use. You can force it to build a new desktop database by holding down Command and Option at the time it first sees the hard disk. The only limitation with this is that any "Get Info" comments you may have attached to things will not be salvaged. (Aside: What we really need is for someone to write a utility to convert the old-style desktop database to the new style in a less painful fashion, preserving the Get Info comments. Any volunteers?) If you ever de-install the Desktop Manager, you will have a similar problem going back the other way. One easy way to do this by accident is to boot up your Mac with a floppy disk, perhaps to install some new software. If you haven't copied the Desktop Manager into the System Folder on that floppy, its services won't be available. Also, I gather that there are some programs around which have managed to be incompatible with the Desktop Manager. I have seen mentions on the net that TOPS is a particular troublemaker. Would anybody care to comment on this? Lawrence D'Oliveiro fone: +64-71-562-889 Computer Services Dept fax: +64-71-384-066 University of Waikato electric mail: ldo@waikato.ac.nz Hamilton, New Zealand 37^ 47' 26" S, 175^ 19' 7" E, GMT+13:00 OS/2 was an attempt to do something useful with the 286 chip. They almost succeeded.
gillies@m.cs.uiuc.edu (11/01/90)
> What's the disadvantage of using the Desktop Manager? > In a word, compatibility. To minimize this problem as > far as possible, the Desktop Manager will not create > its database files on a volume 1.4Mb in size or smaller > (i e all current standard floppy disk formats)--this forces > the Finder to keep on using the old-style Desktop file > on those volumes. That way, you can continue to exchange > floppy disks with people who don't use the Desktop Manager, > without any odd things happening. What about people who move their hard disks between home and work. What if their home machine is too small (1Mb) or too old, or otherwise incapable of running system 7.0?
jvgoodma@wam.umd.edu (John Vincent Goodman) (11/05/90)
In article <2137.272f25f5@waikato.ac.nz> ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University) writes: > >Also, I gather that there are some programs around which >have managed to be incompatible with the Desktop Manager. >I have seen mentions on the net that TOPS is a particular >troublemaker. Would anybody care to comment on this? The manual for TOPS 3.0 specifically mentions that TOPS will not load when using Desktop Manager and advises you to remove DM. (Not a feasible solution if your disk has 2900 files...) I called Sun Microsystems and was told that people were renaming DM to load after TOPS and using both successfully. However it was made clear that this is not officially supported by Sun Micro- systems. +++++ +++ + John