Last updated: 31 March 2007

Welcome to the AutoStar feedback page. This page is intended to provide user comments on using the Meade Autostar #494, #495, #497, cables, and the AutoStar updater software. See the AutoStar Info page for information from Meade and other users on the AutoStar, cables, and software. Send your comments and tips to Remember, tips described on this site may invalidate the warranties on your ETX and accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Subject:	Putting Comets In Autostar 497
Sent:	Friday, March 30, 2007 06:22:32
From:	Cafarella, Edward M. (
I know this is probably a question for Dick, but here goes.  I've been
desperately trying to put comet 2006 VV2 in my Autostar the past few
days and I don't think I've been successful.  I found the relevant
information on the Harvard website 
and copied the line for VV2 to my computer as a text file.  I then tried
two ways to get it into Autostar:  the first was to import it form the
file menu in the ASU program.  The program asked me the right question
(type of object) and I replied "comet" then hit OK. and the box went
away.  But after that, nothing.  The comet didn't appear in the left
hand box and I don't know if it loaded or not.  I went ahead and saved
to the handbox but it wasn't there.  The second way I did it was to drag
and drop the file to the ASU program.  Same thing happened, I answered
"comet" as the type and nothing happened after that.  I also tried to
manually enter the info following the procedures on your site but one of
the items the Autostar was asking me to input was not listed in the
instructions.  I can't remember (I'm at work now) what it was but it was
either the second or third item the Autostar asks for.  Any idea on what
I'm doing wrong?
Mike here: I haven't done that in recent versions but the article "Adding Comets" on the Helpful Information: AutoStar Info page might help. Also the articles "How to use the 3.x Updater" and "How to use the Updater: Manipulating Libraries" will probably help.


Thanks Mike, I actually figured it out.  I mistakenly put VV2 in as a
comet and it's an asteroid!  Funny thing about it is that the updater
won't alert you of that mistake, it just does nothing.
Thanks again,

Subject:	Rubber banding
Sent:	Friday, March 30, 2007 05:42:10
From: (
I am experiencing rubber banding with my ETX 125. I understand the
procedure to correct this is to:

4) RE-SET PERCENTAGES (only if necessary).

I had my scope Supercharged by Dr. Clay a few years ago and had several
touring programs installed in the AutoStar.  My question is, if I do a
Reset, will it wipe out all those touring programs?

Is there another procedure to fix the rubber banding without doing a

Dr. Clay provided a copy of the touring programs on a CD but I do not
have any of the cables needed to download them from my computer to the
AutoStar, if Resetting does erase them.

Jack Fox
Mike here: A RESET returns the AutoStar to its factory default condition. So the tours will be erased. However, you do NOT need to always to the RESET step; just a TRAIN DRIVES will usually cure the rubberbanding. If TD doesn't cure it, then a CALIBRATE MOTOR followed by the TRAIN DRIVES is in order. Only if necessary should the RESET be done, followed by the CM and TD steps. As to a cable, you can easily make a #505 serial cable (see the Helpful Information: AutoStar Info page). If your computer has only USB you will need a serial-USB adapter but not all work with the AutoStar Update application (see the article "AutoStar and USB" on the AutoStar Info page for more on this).


I will follow the instructions without doing the RESET. 
If these procedures do not improve the problem, 
I would rather keep the tours and live with the rubberbanding.


Subject:	LX-90 10" tracking erraticness ?
Sent:	Thursday, March 29, 2007 14:41:45
From:	Mika Maanselka (
I'm a LX-90 10" owner from Finland, Europe and I've been checking you
webpages. So thanks for the great page's! I was wondering if you could
help me out with a problem that I have on my LX-90. When using ALT/AZ
configuration for viewing, tracking is great. The other day I aligned
the scope with "Two Star" alignement (Alkaid and Capella) and me and my
friend grilled some chicken while starting our observation night. Before
eating, I had slewed the scope to M-101 and we ate + drink wine for over
an hour and after that, looking into the ocular, M-101 was still dead

Now I received my Polar Wedge (ultra wedge) and I have tried to do some
photography. Unfortunately I find it impossible to get the scope to
track even nearly accurately in polar mode. I am very familiar with
"drift alignement" and doing that doesn't help. I keep getting "Pole is
less than 5'" info after "two star" alignement succeeding drift
alignement but testing the tracking using Alkaid as the reference star,
it keeps bouncing erraticly through the R.A axis (first it "rubber bands
to the left and then to the right and so forth"). I can recenter it
using only the left and right keys on the autostar...

I'm getting really desperate with my scope that has costed a lot of
money and can't track on polar mode nearly as well as my previous 400
dollar Maksutov. Please help me Obi-Wan Kenobi.... :)

Best Regards
Mika Maanselka
Amateur astronomer, Kerava, Finland, Europe
Mike here: You might try a One Star Alignment in Polar Mode to get the Polar Axis lined up on the North Celestial Pole. Then do a Two Star alignment. I do this with my LXD75-8"SC and it really seems to help. Also, while it isn't supposed to be required, doing a CALIBRATE MOTOR and TRAIN DRIVES in Polar Mode might alleviate the rubberbanding and tracking oddities (unless there is a mechanical reason such as the axes locks are too tight or the system is somewhat out of balance when on the wedge).


Thank's for your reply. In the case of my telescope, the tracking
problem persisted altought polar alignement was perfect (perfected it
with the good old drift alignement). It's as the RA motor is not running
constant speed, as if it is going slower / faster on and off. Have you
ever heard of tracking motor speed fluctuation problems in Meade LX
series ?

Best Regards
Mika Maanselka

PS. Also tried the one star alignement and two star alignement after
that. The result was pretty much the same as with drift alignement.

One thing I noticed when troubleshooting this issue is that when I set
the Autostar "Targets" to "Terrestial" (disable tracking), and press
MODE for a few seconds to get the coordination display visible, the RA
value keeps running slowly (the decimal digit changes by one about every
three seconds. I interpit that to mean that the axis is turning altought
it shouldn't be ?
Mike here: I haven't tracked the LX90 models that closely. Maybe dirty encoders?
Subject:	Autostar download problems-ETX 125EC and a Mac.
Sent:	Wednesday, March 28, 2007 02:53:26
From: (
Hope you can help.

I have not used my 125 for a couple of years following a house move so
thought I'd update and then start again.

First, with Meade cabling and a Keyspan Mini Port Replicator (UPR112) ,
with the latest driver, I tried Virtual PC6 running Windows 2000
Professional. The Mac is an iBook G3 900 Mhz. I downloaded ASU and
worked through that. The Mac was set not to go to sleep. Autostar is 497
with Handbox version 2.0a.

Every time I tried to update I got a message during the update process
telling me to "check cable, try different port then powercycle Autostar
and try again". I tried with updates 4.2g and 43ed. I was only able to
attempt second and subsequent updates by powering up the Autorstar
holding down the Enter and Scroll down keys as without doing this the
Autostar handset screen was blank.

In desperation I then tried AutorstarX in OSX 10.4.9 with the same
hardware but with the latest Mac driver for the Keyspan only to be told
each time that the Autostar had not responded to the restart command.

I have spoken to my UK Meade dealer (and they don't like Macs) who say
that the handset must have been corrupted from a faulty download and
that I need a new handset costing 150.

So Mike, is it a new handset or do you have a solution for me?

Look forward to hearing from you,

Chris King.
Mike here: I haven't tried AutostarX with 10.4.9 (but will this weekend). I have used my Keyspan Twin Serial adapter and it worked fine from VPC6 and AutoStarX. You might try the StarGPS ( application in VPC and see if it communicates any better. I don't think you need a new handset.


Thanks Mike.
Tried to download StarGPS a few times but each one contained errors. I
have a horrible feeling that VirtualPC has the problems. I'll do a
Thanks again,
Chris King.
Mike here: I haven't tried VPC 6 under 10.4; VPC 7 works fine (but haven't tried the AutoStar Update from there since I use AutoStarX for all my uploads). You could download StarGPS from the Mac side and then move it to a shared folder. Don't install from the shared folder however; copy it to the VPC Windows "hard disk".
Later: I just completed updating the AutoStar on my LXD75-8"SC from version 4.2Ed to 4.3Ed. I did it on my old Apple PowerBook G4/500 with Mac OS X 10.4.9, AutoStarX 1.4, Keyspan Twin Serial Adapter with version 2.2. The LXD75 was powered by a Celestron Power Tank and the PowerBook was running on its battery; this avoids corrupting the AutoStar should the local electric company decide to do some unannounced "scheduled" maintenance (which they have frequently done in the past). No problems; the update took 24 minutes. A few hours later I took the LXD75-8"SC out to look for the passing asteroid 2006VV2. Using the AutoStar 4.3Ed, I did a GOTO to its RA/DEC and managed to see the close approach. Looked neat to watch it crossing the eyepiece FOV. Details at:
I started out with a 35mm Televue Panoptic. When I finally noticed a change in a star pattern I switched to a 26mm and then a 12.4mm eyepiece. Even though the Moon was bright and the asteroid fainter than Mag 10 it was still fairly obvious in the 8", even from home here south of Los Angeles. So, definitely no problems loading the ROM from the Mac with AutoStarX.


Many thanks for your help and information.
Chris King.

Subject:	Sun As An Asteroid Autostar Update
Sent:	Saturday, March 24, 2007 18:34:35
From:	Edward Cafarella (
Hi, I downloaded the "sun as an asteroid" file from your website and put
it on my ETX 125PE's Autostar.  When I went to access it on my scope and
went to the asteroid directory, the "sun" was the only asteroid listed. 
I was wondering if other asteroids should be there and I accidentally
deleted them or is that menu normally blank?  If I deleted them, how
would I get them back and also have the sun on there?



And from our resident AutoStar expert:

From:	Richard Seymour (
Yes, unless you followed the steps in my guide to using the Updater,
you can erase all other User Objects.

The short "how to avoid" is:
start updater
click [retrieve data from handbox]
make the changes to the right-side window
click [send data to handbox].

I suspect you skipped the [retrieve] step, so you totally
overwrote the handbox with whatever was on the right side (i.e.
one Asteroid known as "Sun".)

You -also- wiped out your Comets, Satellites, Tours, User Objects...

You -can- recover (or at least "refill" with new data).
Do the "retrieve" per above.
Then, on the Updater, drop the "File" menu bar.
Choose "Get objects from WWW"
Click and choose what you'd like.   The problem will be
"far too much!" than too little.
Fetch Tours, too.
When you've shuffled what you want to the handbox side,
then click [send].

I -also- use the File menu to "Save handbox" data to a 
file on my disk, in case i need to recover from other, um,

good luck


Thanks for your help Dick and Mike, I managed to get the Tours back on
and the Sun as an asteroid.  I see what you mean regarding the others:
way too much stuff to fit in the tight memory of the Autostar.  Is there
a "recommended" list somewhere of comets, asteroids, satellites, etc. to
put on there?  Or do you just kind of put on what you may want to view
later?  Is there a list of the objects Meade included on the Autostar
form the factory?

Thanks again for your help.



For asteroids, i go for the "lower numbered" ones, since they're
within range of the ETX (Ceres, Vesta, etc).

For Comets, it's harder.. you might put a few of the short-period
ones in, or simply a few biggies (There's Halley, but it's too dim to see).
Then add new ones from the keypad as they're announced.

The "how to add a comet manually" is on Mike's site, too:

I also toss in a number of satellites, since they're fun to chase.
A visit to  gives nightly lists of what's
easily visible.

I don't have the current "factory load" of items, and my own
"original set" is over 6 years old...

have fun

Subject:	autostar 495
Sent:	Monday, March 19, 2007 11:41:08
From:	Paul Zerfas (
I recently purchased a meade autostar 495 at a local camera shop. The
owners manual ststes it sill work with my ext 90 ec, however I get a
message "use etx autostar with this model." I tried to update using
files from Meade and my computer states that it connot find the autostar
unit.I have tried the flash mode and still got a similar message.
Someone is selling 495 units on ebay that have been updated, so I know
it is possible.Any suggestions would be greatly aprreciated. I freely
sdmit that I know very little about this or computers so the simpler the
instructions the better.I am a casual hobbiest, but have followed your
site in the past and have found it to be very helpful.
Thanks in advance,
Paul Zerfas
Mike here: Since the updater is failing, lets address that first. Are you using a real RS-232 port on your computer or a USB-serial adapter? If a USB adapter, note that not all work reliably with the updater application on Windows. You might want to see the article "AutoStar and USB" on the Helpful Information: AutoStar Info page. If a real RS-232 port, check for port conflicts (such as fax software tying up the port). Alternatively, try using the StarGPS application to do the update ( Did you make your own #505 cable or did you purchase one? Do you know it is good? Do you really have a #495 (has number keys on the keypad).
Subject:	Autostar error 'motor unit fault' on ETX-90
Sent:	Monday, March 19, 2007 08:08:21
From:	Roger (
Hi i have a Meade ETX-90and ETX Autostar

it was moving down to a horizontal level (using the autostar keypad)
when the motor stopped moving! The ETX Autostar unit now shows a motor
unit fault when trying to align the telescope!

there is no motor noise (vertical axis motor) and i assume the motor is
not turning! The horizontal axis motor works fine! Has anybody any idea
what may have failed!

eg can i fix it myself?

any help appreciated

Mike here: Have you tried replacing the batteries? Have you done a CALIBRATE MOTOR and TRAIN DRIVES? Do you get an error during the CALIBRATE MOTOR step?


I have replaced the batteries!

it would not move at all in the vertical axis, and motor did not run!
(no sound at all)

and gave motor error when telescope tried to move itself on the ETX

error during the CALIBRATE MOTOR step?  YES

having done some research on-line I took the bottom panel off and moved
the wires going through the hole in the centre gear!

3 or 4 attempts and I had success, it now moves, but i assume a wire is
damaged or loose somewhere between the bottom PCB plug and the motor!
and will probably require replacing

Mike here: Could be a loose or broken wire. You might be able to check further and see where the problem is. Whether you will be able to fix it or not will depend on exactly what the problem is and your skills. Possibly best to contact Meade for a repair.
Subject:	Request for Autostar signals
Sent:	Sunday, March 18, 2007 16:46:22
From:	Neil Maron (
I am wanting to use a Meade 497 controller to drive my own stepper motor
controller. I have Steve Bedair's Meade DS wiring but do you (or anyone)
know what the Autostar is putting out? I.e. is it pulse and direction
for each of the three (ALT, AZ, AUX). Do you know what the max
resolution it supports is? I.e. 1/4 arcsecond, 1/10 arcsecond, or
something worse?
Thank you,
Neil Maron
Mike here: I'll let our resident AutoStar Expert, Dick Seymour, respond.
From:	richard seymour (
First, the Autostar system doesn't use stepper motors.
The axes are servo-driven by simple dc motors with shaft
encoders.  The electronics on each motor card are told
by the Autostar what -speed- to move at.  Then they do
closed-loop control using the shaft encoders to determine
the motor travel.  They also report the encoder counts
back up to the Autostar, so it does see positional data.
The power actually reaching the motor are full-voltage
pulse-width-modulated (PWM) signals, with the frequency
and duty cycle being adjusted to maintain the Autostar-
requested speed.

The entire system is described by Meade's patent  6,304,376
which can be seen at:

The signals on the wires coming from the 497/495/494 Autostars
are modified I2C bus-like commands.  They're addressed data
packets ("motor 1, operate at 320 encoder pulses per second"),
not stepper control signals.

The resolution of the system (as practiced by existing models)
ranges from 0.735 telescope motion arcseconds per encoder
transition (ETX90) to about 0.2 arcsec (4504).  People have
used Steve Bedair's techniques to achieve 0.1 arcsec.
The Autostar's Gear Ratio setting is in units of "encoder
transitions per telescope arcsecond".

have fun


Whoops... i forgot to mention the RoboScope Yahoo group,
who are all working on putting Autostar drives on a variety
of mounts, and who have replaced the Meade motors and final
driver stages with beefier components.

Your question is the inverse of the more usual query:
"how do i replace the Autostar with a PC"?
...and just as difficult.

If you monitor the I2C signals to the motor cards,
you -can- reverse engineer a good chunk of the protocol.
(the patent filled in a lot of details).
Then you could program a PIC-chip or similar to
handle the Autostar's commands.

have fun

Subject:	RE: LX90 vertical motor problem
Sent:	Sunday, March 18, 2007 11:33:10
From:	African Sky (
Thanks for the replay, was away on business and only download my email

Yes I have tried that but no luck. My problem is that I am in South
Africa and there is only one Meade dealer out here and that is about 600
km away. I would like to try easy fixes first and if that does not work
I will have to take it in. Meade doesn't have an email contact and the
dealer just tells me on the phone to bring it in. Any thing else you can
think of? 

Mike here: Have you tried one of the LX90 Yahoo Groups? I think there are some.
Subject:	re: ETX-90 Align
Sent:	Wednesday, March 14, 2007 19:29:12
From:	richard seymour (
You are correct that the new firmware runs the sidereal drive
during alignment.

That behaviour was added -many- years ago.

Whether or not it is "better" is difficult to say.
I remember -not- liking it when the change happened,
but i have also now grown used to it (and it matches the LX200gps).

Since it does track, it means you don't have to worry about
-missing- "center" when you tap your [enter] key.
You can take your time, and slew slowly in from the east towards
the west to avoid the backlash effects.  When you release the
slew key, the star should not move in the field of view.

have fun
From:	Ruedi Eggimann (
Thank you very much for the information- now I am very satisfied and I
enjoy of my ETX-90.

Subject:	Autostar version download
Sent:	Monday, March 12, 2007 13:06:03
From:	Harden Schaeffer (
The other day I downloaded Autostar version 32Ei from your site ( I have
a non-PE scope, so I didn't want all the PE support junk.)  It said, and when I unzipped it I got BUILD32E.ROM.  When I
installed it in the Autostar I got version 30Eb.  What gives?

Mike here: Did you put the file in the Ephemerides folder?


No, I put it in the same folder as the Updater - the latest updater from
Meade's site.  When I got your message I looked in the Ephemerides
folder and saw what was going on.  Talk about a Trojan Horse!  I'll
delete that one and put the 32Ei in there instead.  Thanks, Mike.


And an update:

All fixed up!  Autostar is now loaded with 32Ei.  Again, many thanks.


Subject:	ETX-90 Align
Sent:	Monday, March 12, 2007 01:09:09
From:	Ruedi Eggimann (
First sorry for my English.

I am owner of an old ETX-90 an i have updated my Autostar 497 with
Version 4.2 G.

If i want to align the Telescope with method Easy or two Star, i have
the problem, that the motors always run (wants to follow the stars,
without to be yet aligned) while centering the stars. And then it is
extremly difficile  to center the star.With the first versions, the
motors always stopped and were quiet and only worked when pushing the
buttons. Is this a mistake of the hardware (i made a service on my ETX)
or is that now normal?

Thank you for the answer

Rudolf Eggimann, Bern Switzerland
Mike here: After doing the update did you CALIBRATE MOTOR and TRAIN DRIVES? I always recommend doing that following any update of the AutoStar ROM.
Subject:	ETX AUTOSTAR Updates
Sent:	Sunday, March 11, 2007 17:55:37
From:	Neal Rothchild (
I have an ETX 90 EC, and autostar, purchased at the same day, about 4
years ago.

Have not used in last 2 1/2 years, and just wanted to know if I need to
do anything maintence wise to the scope, and if I should do any update
on the autostar.

Specifically, if I don't do anything to the autostar, will it still
function correctly?

If I do update this, how? I have never done this.

And, lastly, if I do need to update, what do I need to purchase, ( and
where) for this to work?
Mike here: First, if you left the batteries inserted, remove them, check the battery compartment for any leakage from the batteries and clean it up if necessary. Then loosen the axis locks and slowly move the telescope back and forth and up and down, hard stop to hard stop, several times to loosen up the lubrication. Next insert fresh batteries, do a CALBRATE MOTOR and TRAIN DRIVES on the AutoStar. For now, that's all that you might need to do. The AutoStar will still perform properly. If you do want to update you will need to buy or make a #505 serial cable (info on making one is on the Helpful Information: AutoStar Info page). If your computer has only USB you will need a USB-serial adapter (see the article "AutoStar and USB" on the AutoStar Info page; note that not all adapters work with Meade's updater application. Lastly you will need an updater application; Meade's (Windows) or AutoStarX (Mac OS X), links on the AutoStar Info page. You could also use the StarGPS application (Windows; to do the update.



Subject:	LX90 vertical motor problem
Sent:	Sunday, March 11, 2007 00:02:28
From:	African Sky (
Hi, my LX90 just go round and round when looking for something.(Vertical
control) I reset it, retrained the drives and anything else I could find
in the manual that might make a difference. A new board was installed
and shortly after that it started acting up, first on the odd occasion
but now most of the time. Could it be the board or do you think it might
be something else. Please advice.
Ernst Marais
Mike here: I don't have a LX90 so don't know if this will cure the problem or not but have you done a CALIBRATE MOTOR?
Subject:	re: Autostar Updater ASU can not connect with Autostar
Sent:	Thursday, March 8, 2007 22:04:33
From:	richard seymour (
Two suggestions:
(a) download the -new- Autostar Updater (v4.6) from Meade's site.

(b) try StarPatch, a free updater written by someone else.  From:

StarPatch cannot update the objects, but it can update the firmware.
Like Mike, I suspect some other program in your PC is "stealing"
the COM port from ASU.  ASU does not hold the COM port very strongly.

good luck
From:	Fernando Gomez (
Thank you Dick and MIkefor your assistance.

I could fix the problem reinstalling Autostar Updater. Now everything 
works OK


Subject:	Autostar 494 update problem ??
Sent:	Wednesday, March 7, 2007 02:09:09
From:	Mark Thomas (
I have a Tal2M with its original mounts converted to GOTO with motors
and hand controller from a Model 4504. It had been working really well
173 tooth worm gear hobbed onto a stack of 5 ally discs from computer
hard drives riveted together as my small lathe could handle the spindle
but not a large enough disk (tal ota is quite heavy) and original 180
gear with 1.6:1 stepdown and 2 clutches so both original slo mos work if
needed. Last night I was updating the satalites catalogue when my pc
crashed now I just get the top row on hand controller as row of red
squares holding enter and scroll (not move) down doesn't do anything. Is
this version of 494 different or have I killed it.      Cheers  Mark
Mike here: Unfortunately, the AutoStar memory is apparently now corrupted as a result of the computer crash. Meade has not made any user-installable software available for the #494 so your choices are rather limited. Get a new AutoStar, ideally a #497 which is user recoverable, another #494, or contact Meade for a repair.
Subject:	Autostar Updater ASU can not connect with Autostar
Sent:	Monday, March 5, 2007 18:08:22
From:	Fernando Gomez (
After several attempts II couldn't connect my Pc with Autostar
Folowing the instructions on your website I had    checked  previously
the cable and the Serial port and everything looked to work fine.

I checked the Serial port with Windows hyperterminal and also with
lookRS232 software. . Applying the basic commands of the Meade  protocol
I   could move   "by hand " the motor (Setting the target  Alt, RA and
Moving the motor to this target)

I  also could set the scope to  a selected object (RA, dec) using the
software Cartes du Ciel.

But when I tried to work with the AutostarUpdate (ASU) v4.3 I coudn even
connect with Autostar. The messages "Could not connect with Autostar"
followed with the message "Could not find Comm port" appear again and
Do you have any tip to fix this problem?
Thanking in advance for your help
Fernando Gmez
Montevideo, Uruguay 
Mike here: Are you using a real RS-232 serial port on the computer or a USB-serial adapter? If an adapter, not all work well with the ASU application; see the article "AutoStar and USB" on the Helpful Information: AutoStar Info page. If you are using a real serial port then it could be there is some software (typically fax software) tying up the serial port.

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