I hope you don't mind me dropping in, although not all aspects of the
question are really clear to me...
At 15:25 18-8-01 -0500, you wrote:
>Christof Lange wrote:
>>
>> Is there a way (utility) to find out the maximum size of the RAM
>> disk on a system after booting to it? What will be the optimum size
>> of the RAM in relation to CACHE size and performance.
When made my first arachne ramdrive diskette (for a 286 diskless
workstation with only 4 mB) I didn't have much of a clue, but was lucky
enough to find out that a cache isn't worth anything as you don't have any
diskaccess to speed up (or only the diskette read during boot, but that's
not a problem if you keep the diskette defragged). Now that I have
experience on a 486 with 8 mB and a hdd, There are a couple of additional
possibilities:
1. mail and download path to hdd: small cache (<200kB) is sufficient to
load mails, for downloads a cache is not needed because the overall speed
is limited to modem speed, rather than disk write.
2. RAM is needed for virtual screens; its size depends on the choosen size
of those VS.(Of course you'd rather turn VS off than swap to disk)
3. Should you want mail and downloads straight to diskette, remember that
caching is readonly for removable media
>
>There are a couple of ways to get around this problem.
>The easiest way is to require the user to have 8Mb ram minimum and just
>make a 5120kb ramdisk - but the self-extracting Arachne.exe will refuse
>to extract in less than 6Mb (6144kb).
>
>Another method uses FIND and MEM (or QEMM) to test for the reported
>memory size string. Since you are providing the mem management software
>it should be little trouble to fine tune it to the exact search string(s).
>I suggest you search for the strings representing 1M bytes to 8M bytes in
>1Mb steps and if you don't find one, assume it is more. <g> There may be
>some reason to also search for 64k less than each of these numbers.
>
>There is probably some utility available to do this, but you will still
>have to interpret its output in your autoexec, so it won't be much help
>UNLESS you can find a utility that returns an errorlevel indicating that
>there is more than some requested amount available.
>
>Here the problem is you won't get that info before your autoexec runs so
>you can't load the ramdisk in config.sys if that is the type you use.
>
>TDSK, however, loads in autoexec (or later) and has the necessary copyfree.
>
>If there are many partitions on the HD, you need some way to determine what
>the RD designator is. I prefer to discover this rather than loading extra
>software to set the drive letter to some obscure value like Z. Lastdrive Z
>takes up valuable memory space too.
>
>Try this:
>For %%X in (C D E F G H I J K L M N O P Q R S T U V W X Y Z) if exist
%%X:\nul
> SET RDRV=%%X: (one line) (no space ^)
>
>As you can see, RDRV will change every time the test is true and the last
>value must be it.
>Or maybe you could use FIND on the output of your RD creation ?
>
>Finally, there is a BIG problem with FAT32 drives. If your supplied OS
doesn't
>recognize FAT32, you may get the RD created as C: Goodbye Windows !!
>So, before transferring anything to the RD, check to make sure it is empty.:(
Here's where I don't really get it: If you want to make a diskette that
runs arachne on a random system (that may have up to 4 physical drives),
why not just use xmsdsk.exe from autoexec and point it to drive g: or h:?
If you allow a choice for the mailpath to either a hdd or diskette, (using
multiple .acf profiles), you'd have to fill in some paths manually anyway,
so default all to the ramdrive and add a warning that a reboot would lead
to totall loss, seems appropriate to me.
>
>- Clarence Verge
>--
>- Help stamp out FATWARE. As a start visit: http://home.arachne.cz/
>- The internet is infected - Windows is a VIRUS !!
>--
>
>
($400 is ten times the price of an efficient Arachne system...)
Arnhem, Netherlands,
Bart Buitinga
>
