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From: chuqui@nsc.UUCP (Chuq Von Rospach)
Newsgroups: net.micro.mac
Subject: Re: Disk eject/insert (ramdisks...)
Message-ID: <2494@nsc.UUCP>
Date: Wed, 20-Mar-85 13:48:26 EST
Article-I.D.: nsc.2494
Posted: Wed Mar 20 13:48:26 1985
Date-Received: Fri, 22-Mar-85 01:08:54 EST
References: <265@ihlpg.UUCP>
Reply-To: chuqui@nsc.UUCP (Chuq Von Rospach)
Distribution: net
Organization: The Village
Lines: 54
Summary: 

In article <265@ihlpg.UUCP> jcbood@ihlpg.UUCP (Jaap Bood) writes:
>(btw, I don't agree with the
>review of the ramdisk in the march issue of Mcworld; I have a single disk
>Mac and the Ramdisk solves 80% of the swapping problem, plus has a number of
>other advantages - fast Mcwrite prints; fast launch etc)

I'm using ramdisk used in the Macworld review, and I can't decide if it is
a royal pain or if it is a Godsend. My setup is 512K with 2 drives, so I
don't have a swap problem that someone with a single floppy would. There
are definite tradeoffs.

The main disadvantage I see is that the ramdisk is smaller than a normal 
floppy. This drives me up the wall, since I can't fit everything in a
ramdisk that I would normally fit on a floppy. This is most noticable when
I'm hacking-- Mac C and the MDS stuff unfortunately all want to share a
floppy or the various transfers in EXEC doesn't work, and the preliminary
version of EXEC doesn't seem to work unless it is on the disk with the 
system file-- The result is a 395K disk (with no fonts and minimal DA's)--
I couldn't cram that into a Ramdisk if I wanted to.

On the other hand, when I can put the system stuff and application on the
Ramdisk, its a lot nicer (I do this with MacTerminal and MacProject)
because I only need one floppy to work with the system-- hauling MacDuff
around becomes that much easier. Again this works because neither of these
applications use a lot of fonts-- so the system file is smaller. For
macpaint and macwrite, where I need my fonts and my DA's, my system file is
about 250K, so the applications move back to floppy and all the system
stuff goes to RAMdisk. 

At last look I was maintaining three different variations of the system
file. I'd REALLY like to keep one, but I haven't found a way to do this
considering the 'small' disks (I find it amusing that someone who used to
think an 8K IMSAI was a wonderful machine could complain about half a meg
of memory and 400K floppies...).

>Now to end the good news, I have sometimes the following problem:
>I bring up the system with a startup disk, which creates the ramdisk
>(startup application).
>I execute SWITCH to make my ramdisk the boot-disk, and eject the startup
>disk.

I think the switcher is trying to make use of the same memory that your
ramdisk is-- remember that it partitions off memory into segments to allow
you to pop back and forth between different applications. There is a good
chance that it uses some part of high memory to stores its data and that is
stomping on your ramdisk. I seem to remember reading somewhere that the
switcher and the ramdisks weren't compatible, but I don't know where...

chuq
-- 
Chuq Von Rospach, National Semiconductor
{cbosgd,fortune,hplabs,ihnp4,seismo}!nsc!chuqui   nsc!chuqui@decwrl.ARPA

Be seeing you!