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From: sjl@amdahl.UUCP (Steve Langdon)
Newsgroups: net.micro.mac
Subject: Re: Disk eject/insert (ramdisks...)
Message-ID: <1319@amdahl.UUCP>
Date: Thu, 21-Mar-85 00:42:57 EST
Article-I.D.: amdahl.1319
Posted: Thu Mar 21 00:42:57 1985
Date-Received: Fri, 22-Mar-85 02:19:06 EST
References: <265@ihlpg.UUCP> <2494@nsc.UUCP>
Distribution: net
Organization: Amdahl Corp, Sunnyvale CA
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In his posting Chuq says:

> 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.
> think an 8K IMSAI was a wonderful machine could complain about half a meg
> of memory and 400K floppies...).

His analysis of the situation is the obvious one, but it is not correct.  I will
explain by describing my current C compiling setup. I use the following volumes:

	RAMDisk - System, C compiler, Exec, Edit, and a program called "Finder"
		  that I wrote.  It calls SFGetFile for 'APPL' type files and
		  launches the selected file.  It is much smaller than the real
		  Finder.
	Drive 1 - Linker, RMaker, real Finder, and all the .REL library files.
	Drive 2 - .h files, my source and associated files(ie. .job and .link)

To get all this to work you have to use the Menu or Resource Editor to edit
volume names into the transfer menus of the various parts of the Mac C system.
You also need to put volume names in the .job and .link files to direct the
programs to look in the right places.

The following section of his note seems to me to represent a missunderstanding
of the original posting.  I do not think that the "SWITCH" refered to is the
Switcher.

> >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...

-- 
Stephen J. Langdon                  ...!{ihnp4,hplabs,sun,nsc}!amdahl!sjl

[ The article above is not an official statement from any organization
  in the known universe. ]