Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!endor!olson
From: olson@endor.harvard.edu (Eric K. Olson)
Newsgroups: comp.sys.mac
Subject: Re: Possible LSC improvements
Message-ID: <2989@husc6.UUCP>
Date: Tue, 13-Oct-87 10:20:59 EDT
Article-I.D.: husc6.2989
Posted: Tue Oct 13 10:20:59 1987
Date-Received: Wed, 14-Oct-87 06:49:12 EDT
References: <2071@sfsup.UUCP| <170026@acf3.NYU.EDU>
Sender: news@husc6.UUCP
Reply-To: olson@endor.UUCP (Eric K. Olson)
Organization: Lexington Software Design
Lines: 43

In a recent article David Fry writes:
>In article <2638@batcomputer.tn.cornell.edu> eacj@tcgould.tn.cornell.edu (Julian Vrieslander) writes:
>>I asked one of the folks at Think whether LSC was smart enough to
>>flush the cache before a project is started up from the "Run" command.  He
>>claimed that this was not the case, and that there was no way that LSC
>>could tell whether the cache was enabled.  He said that he did not trust
>>the RAM cache well enough to use it for his own development work.
>
>Two funny things about this: first, it is certainly possible
>for LSC to determine if the cache is enabled.  How does the
>Control Panel do it? Divine intervention?  I wrote an FKEY to
>toggle the cache setting it is trivial to check for the cache.
>
>Second, I have used LSC plenty with the cache on and I have
>crashed it just as often and I have yet to lose a single
>character of source this way.  
>
>Ever since Apple came up with the cache it has been given a
>constant bad rap, in my opinion. I think it's a safe, great
>idea.

I have used the cache without a problem since it became available
in the System.  I think it is very safe to use with LSC, because
LSC does a _FlushVol (in LSC CODE #10) prior to running the project.
This (I assume) flushes the cache; it wouldn't be a very useful
system call otherwise.  

The cache is also probably quite safe for general use also, since
_InitApplZone also calls _FlushVol, and _InitApplZone is called
at every Launch.  (In fact, LSC does two _FlushVols because
of this).  If you're program crashes and use use one of the
many techniques to invoke _ExitToShell (FKEYs, debuggers, or SM 0 a9f4 G 0
in the minidebugger in the 128K & 256K ROMs), then the Launch of the
Finder will also call _FlushVol.

Then again, if _FlushVol doesn't flush the cache, none of this is
any good.  But I'm quite sure it does.  Anyone at Apple care to
comment?

-Eric

Eric K. Olson     olson@endor.harvard.edu     harvard!endor!olson     D0760
   (Name)                (ArpaNet)                 (UseNet)        (AppleLink)