Amiga Tools 4/Amiga Tools 4.iso/tools/disk-tools/harddisk/quiet-scsi/quietscsi.doc

Text File | 1996-02-26 | 12KB | 280 lines

                                 QuietSCSI

            a program to prevent SCSI drivesfrom making noise

                                release 1.1

                    by Franz-Josef Reichert, 10/20/1995


UNLESS OTHERWISE NOTED, ALL FILES ARE Copyright © 1994-95 by F.J. Reichert.
All  Rights  Reserved.  WARNING:  THIS IS *NO* PUBLIC DOMAIN PROGRAM, BUT A
COPYRIGHTED PIECE OF SOFTWARE.

Franz-Josef Reichert
Kuchlingerstraße 13
D-66271 Kleinblittersdorf, GERMANY
FAX:   [phone]
eMail: [e-mail]

*** WHAT'S NEW FOR 1.1? ***

    This is release 1.1 of QuietSCSI. A release which shouldn't have
happened at all, though, since only two (2) people actually sent me a
donation for my work. Would you care about to invest further development,
time, money to a project only two people are interested in? Well, I'm a
hopelessly amiga addicted fool, so *I* did!

    Please, make me believe that it's worth even more effort! ;-)

    MANY more people asked for more features. I had to answer several
dozends of questions, but nearly all people obviously using my program all
days never sent a donation. Anyway, the most popular enhancement requests
made their way into this release:

· Recognizes "special" drivers "ALF.device" and "oktagon.device" and
handles them properly. In earlier versions, QuietSCSI refused to work on
those hostadapters if there was more than one SCSI target installed. On the
other hand, Oliver Kastl (the programmer of the original ALF-software) told
me that there's some QuietSCSI-like feature already built in, so there
should be no need to use QuietSCSI with this software, anyway. Don't ask
me...

· Additional code to make removable media user happy (well, almost), such
as SyQuest or some other magnetooptical toys. It was introduced in
QuietSCSI 1.1. Removable media support *is* tricky. Shortly after the drive
is turned off, a requester will appear on workbench screen to ask for
restart (you need at least 2.0 ROMs (V37)). The choice is to leave the
requester hanging around as you like or satisfy it, which will result in a
restart. As long as the requester is up, all driver related commands will
be queued until the request is satisfied. This will of course suspend any
command waiting for queued driver requests to complete. For example, issue
the command "C:Info", "C:Dir" etc. and it will not return until a pending
restart requester is satisfied. Warning: Workbench might even be blocked!
On the other hand, note that the drive will never be stopped when there is
no medium inserted. This is usually no problem since most changeable media
drives stop their motors in this case, anyway.

    +-------------------------------+
    | QuietSCSI            |
    +-------------------------------+
    |                |
    | Restart requested on        |
    |                |
    | removable media        |
    |                |
    | "scsi.device" unit 0        |
    |                |
    +-------------------------------+
    |          +---------+        |
    |          | Restart |        |
    |          +---------+        |
    +-------------------------------+

If you consider the requesters and the necessary (manual) restart a
problem, please don't use QuietSCSI on these drives at all! Other than some
people might think, this topic needs *no* further discussion. It's a matter
of fact that the filesystem will always try to re-read a volume directory
tree once it received a diskchange event (caused by the STOP command
QuietSCSI issues), and there's *no* way to prevent it from doing that. All
QuietSCSI can do about this is to queue all commands, and thus suspending
the filesystem from further investigations. Other than with
non-removable-media drives, there is no chance for an automatic restart,
sorry.

· LUN numbers are correctly handled now. At least for device drivers being
able to handle them properly.

· -h Option brings up the usage help text.

*** FAQ, COMMOM PROBLEMS SOLVED ***

· Please don't ask me whether there might be a chance of QuietSCSI to work
on some AT/IDE-style devices. I simply don't know. QuietSCSI MAY work on
those drives, IF the driver is designed to emulate some related SCSI
commands AND if the drive used has some suitable command equivalents the
driver software might want to call. If not, it probably _won't_ work. Try
it. I tried it on my A1200 with a Seagate IDE drive. No go, ha! Don't blame
me if it doesn't work. This software is intentionally named Quiet-S-C-S-I,
not QuietIDE, nor QuietAT, nor QuietATAPI.

· To make QuietSCSI work on GVP hostadapter cards equipped with the new
Guru-ROM (omniscsi.device) by Ralph Babel, put the following command in
your startup sequence:

    OmniScsiCtrl <unit> NOSCSICMDINT

_before_ you start QuietSCSI. This topic is discussed in the Guru-ROM's
user's manual FAQ chapter, too.

*******************

· Disclaimer

The author disclaims all warranties, expressed or implied, including, but
not limited to, any implied warranties of merchantability and/or fitness
for a particular purpose. The author does not warrant, guarantee or make
any representations regarding the use of, or the output from, the program.
You rely on the program and output solely at your own risk. In no event
will the author be liable for any action, including lost profits,
incidental or consequential damages arising out of the use or inability to
use this software, exceed the possible shareware fee you paid for this
software, even if the author or an authorized distributor of this software
has been advised of the possibility of such damages.

· Distributing this program

This piece of software, including all accompanying files in the archive, is
what some people tend to call »Freeware«. This implies:

This program may be freely DISTRIBUTED, by any means, as long as there are
no charges specifically for the program. Charges for downloading from
electronic BBS systems or network services, or charges for copying and
media for freely redistributable software libraries are certainly
permissible. The entire archive has to be left intact and unchanged. You
must not distribute any changed or imcomplete set of the original archive.

· Using this program

This program may be USED for any purposes, commercial, personal, public,
and private, as long as ALL of this text, all files, copyright, mailing
address, and this notice are retained in their entirety. It is provided
without warranty of any kind, so use it at your own risk!

This piece of software, which includes all accompanying files in the
archive, is what some people tend to call »Giftware«. This implies:

    · You may use it as often as you like

    · You may use it as long as you like

    · You are *NOT* obliged to pay anything for using it

    · You *can* send a donation to the author, if you feel
      so or if you like to do so

    · If you like to send a donation to the author, you can pay any
      amount you think that this piece of software is worth it

    · Thank you for supporting a poor programmer, who still insists in
      writing quality amiga software ;-)


· What this program actually does

· The problem

Do you remember your first Amiga 1000 computer? Everybody asked you 'Is it
really on' when they saw it first, since it was so q-u-i-e-t. I'll never
forget that perfect feeling having a nice, quiet computer on my desk. Nine
years later! Computers make noise. Computers which contains a harddisk make
even more noise. Computers containing several harddisks make even much more
noise. And they burn energy! Today, people spend a lot of $$$ to buy
themselves screen blankers. And cooling fans which make less noise than the
el-cheapo thingies all power supply manufacturers use. Oh well, everybody
has a low power monitor and computer. But nobody realized, that a harddisk
spins most time of the day without reading or writing a single byte! It
just spins, burns a lot of energy, and makes noise.

Can you sleep in the same room when your computer is on? I can not! The
harddisks make too much noise. Well, the power supply fan makes noise, too.
But since I got a temperature controlled model, I can stand it much better.
And there's another problem. The power led. Yes, it's so bright that I can
read books!

· The solution

Speaking of SCSI harddisks, there is a mechanism to switch the motor off.
It will just stop to spin as if you switched your computer off. But the
drive is not dead. It's just q-u-i-e-t. It won't allow you to read or write
data, though. But the controller electronic on the harddisk is still alive,
and it might get a command to restart the drive at any time. Then it will
behave just as if you switched your computer on. The motor will spin up
again, and the drive will be ready to read or write data.

This little program does exactly this. It monitors all read and write
accesses to the drive. It also monitors all input events. If there is
inactivity for a certain period of time, it will spin down the drive motor
and dim the power led. If the next command arrives, it will spin up the
motor and switch to led back to bright.

In other words: Leave your amiga alone for some time, and it will switch
the harddisk's motor and the power led OFF. Come back to your amiga after a
while, continue your work. You won't realize any difference, the harddisk
is still quiet. But the next time you try to read or write data from the
drive, it will switch the power led and the motor ON, and your harddisk
will spin up again. That's the whole magic. It save energy, and it saves
noise.

Maybe you run a BBS and only 2-3 users will log in during night? Or your
computer is alive to catch FAXes all nights, which will only happen once a
week or so? So this is for you!

· Starting the program

This one is really easy to use. Just put it to your startup-sequence (or
even better: user-startup):

    RUN <NIL: >NIL: quietscsi [-h] <device> <unit> <seconds>

where

    <device> is the name of your SCSI driver, e.g. scsi.device,
or gvpscsi.device. Default is "scsi.device".

    <unit> is the unit number where you harddisk is connected to. You
can figure this out by starting HDToolBox, for example. Default is 6.

    <seconds> is the number of seconds for the inactivity timeout.
Default is 900 for approx. 1/4 hour, maybe you'd like another value. You
shouldn't choose the value too low, though. Switching the motor off and on
very often burns more energy and shortens your harddisk's lifetime (Well,
don't go nuts about that ;-)). In the current release, the timer is quite
inaccurate, since it doesn't compares with the system clock, just counts
timer requests of one second. So it may vary, maybe 900 means 16, 17 or
even 18 minutes. It is guaranteed to count always some seconds more, but
never less. This isn't a big problem in general. I was just too lazy to fix
it, maybe in the next release ;-).

    [-h] is optional and will bring up the default help text.

· Quitting the program

You might want to try to send a <Ctrl>-<C> signal to the process. Either by
typing that to the shell you started it from (but that's not the way you
should do it, since it blocks a window), or by using the shell command
»break«. This *may* remove the patch. It is not guaranteed that it will
succeed, since there might be some requests in the queue which need to be
handled first. Just try a while later. Anyway, there shouldn't be a need to
remove the patch while your system is alive. I merely added that option for
debugging purposes. Well, maybe I shouldn't have told you that at all ;-).
Don't bother me if you encounter problems related to this.

· Things to do

You can send me a donation if you like. That's what *you* can do ;-).

Now the things that *I* plan to do when I notice that some people like my
program:

    · More accuracy for the timer

    · Add TSR startup code

    · Add some more command line options

    · Find a new girlfriend

    · Implement a commodity interface, perhaps a GUI which lets
      the user switch the drives off and on, select an new
      timeout and all those useful and marvellous things

    · (...)

Maybe you have some more ideas! Let me know. Have fun using QuietSCSI, I
use it all the day. It's small, but it's probably one of the most useful
tools I ever wrote.

<EOT>