[comp.sys.apple] Questions about GS System Disk 5.0 summary

DCS100@PSUVM.BITNET (David C. Schweisguth) (08/27/89)

     A summary of my questions and the answers I received follows. Thanks to
Messrs. Andy McFadden, Cary Farrier, and particularly Dave Lyons for their
lengthy, thorough, and helpful responses.

In article <89233.162153DCS100@PSUVM> I wrote:

>     1) What are the purposes of the following files: [listing of several new
>to System Disk 5.0 ...]

The July 89 release of GS/OS Tech Note #1, just out from DTS, describes the
contents of all three disks -- no sense duplicating it here.

>     2) How does Expressload do its thing? Does it depend on the physical
>placement of disk blocks, and if so will it be mucked up by copying
>Expressloadable files with utilities other than the newest Installer or
>Finder?

No, it doesn't depend on the physical placement of disk blocks. Expressload
uses a different object module format *within* the file, and not on any
physical block addresses, so you should be able to copy any Expressload file
(without a resource fork, see below ...) with any application. You'll get the
maximum benefit if the file is not "fragmented" much, since a large part of the
speed-up comes from being able to do Reads of large chunks of the file at a
time, which usually translates to doing multiple-consecutive-block reads down
at the device-driver level.  (The SCSIHD.Driver and APPLEDISK3.5 drivers go
Fast when they can do multiple-block reads.)

>     3) Virus Detector V1.2 always detects a virus on copies of my presumably
>virgin System Disk 5.0. It continues to do so after it has supposedly fixed
>the boot block. This happens when VD is the first or last file in System/
>System.Setup; I haven't tried other placements. I guessed that a) the boot
>block has been changed (as with GS/OS V2.0) and b) VD can't write over it for
>some reason, but that's only a guess. Any ideas? (No, the disks on which I've
>tried this have not been write-protected.)

Interesting--I hadn't heard of this before, but I believe your guess is
correct.  The boot blocks *have* changed again (this time only to fix an
obscure bug that only appears if your PRODOS file is Sparse and actually
requires the zeroed-out bytes to be loaded into RAM).
     That explains why VD 1.2 doesn't like your boot block.  So why can't it
write a "good" boot block back to your boot disk?  Because the Sys.Resources
file is Open, and you can't write blocks to a volume with open files on it
under System Software 5.0.

>     4) Is the file System/Start.GS.OS supposed to be unlocked (if locked) or
>written to during normal GS/OS operation? I normally keep all my non-document
>files locked, and Start.GS.OS won't stay that way. The modification date is
>still June 14th. This happened with System Disk 4.0 as well, but I never got
>around to asking anyone about it.

GS/OS keeps the "speed" of the boot thermometer in the auxiliary type of the
Start.GS.OS file, so it's doing a SetFileInfo on that file.  Apparently it
doesn't bother to first do a GetFileInfo to preserve the access word.  No big
deal--just a little weird.

>     5) I attempted to copy the entire system file-by-file from one 3.5" disk
>to another using Copy II Plus. Only one block each of Sys.Resources,
>Ctlpanel.NDA, Cdev.Data, and each of the CDevs made it to the target volume.
>Copy II Plus did not report any errors. The Finder from System Disk 5.0 copied
>the same files correctly. Are these (gulp) forked files?

Yes.  ("Extended" is the official word.) Apparently the version of Copy II Plus
you were using [8.3] looked at the ProDOS storage type, saw that it wasn't a
Tree file or a Sapling file, and decided it must be a Seedling file--and only
copied the key block.  Whoops!  No idea if later versions of Copy II Plus know
about extended files.

>     6) There seems to be a bug in the standard file opening dialog. I have
>two 3.5" drives, so when I want to load an existing document into an
>application I normally boot the system from drive 1, launch the application
>from drive 2, put the disk with the document in drive 2, and then open the
>document. Under GS/OS V3.0 this sometimes hangs the system, as if it were
>still expecting the application disk in drive 2. This only happens when I do
>this immediately after launching the application (any application); after one
>successful dialog everything works fine. I can work around it by selecting
>Load, Open, or whatever with the application disk still in drive 2 and then
>tabbing to the new disk, but I shouldn't have to. Has this happened to anyone
>else? Any ideas?

[A chorus of responses to the effect that these things happen all the time.]

>     7) What would happen if I deleted the Control Panel NDA and its related
>files (Ctrlpanel.NDA, CDev.Init, and the CDevs directory)? I haven't tried yet
>but I might want a really stripped-down system some day, and they take up a
>lot of space for something I don't use much.

Amazingly enough, if you delete all that stuff, you get a disk that doesn't
have a Control Panel NDA.  This won't interfere with the system proper, but
you won't be able to do Cdev-dependent things like choosing a printer.

Thanks again, all.
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