Last updated: 27 January 2001

Loading 2.1ek with A2.1

From: rick@pinefields.com (Richard B. Emerson)

[Author's note: The following procedure was done using an IBM Thinkpad laptop and an ETX-90EC telescope. The scope's Autostar was loaded with firmware version 1.3 when the scope was initially received. It has since been loaded with 2.0i, 2.0h, and 2.1Ek several times with both Autostar Updater A2.1 and A2.3.

What follows is a work-around to deal with problems in updater software. As far as I know, Meade does not recommend or endorse the use of firmware 2.1Ek with updater A2.1. If you are uncomfortable with working with potentially buggy software, do not attempt the following. At the least you can disable your Autostar and, if you cannot do a Safe Load procedure, you may have to send your Autostar to Meade to have it re-loaded. There is, in short, some risk in following the procedure described below.]

Installing 2.1Ek firmware with Autostar Updater A2.1:

Autostar Uploader version A2.3 ("A2.3") has some problems that basically make it unusable for uploading anything beyond the basic Autostar firmware version 2.1Ek ("2.1Ek"). Specifically, it's possible to try to upload more objects (comets, asteroids, and satellites) than can be handled by 2.1Ek. This problem usually becomes apparent while loading satellites (the last group of objects to be loaded). An error message "Failed to write from LibSatellite.ROM at record " is displayed. Hitting the OK button (the only choice), it appears that A2.3 has resumed operation by uploading any tours present (usually Tonight's Best, How Far..., and Messier Marathon). On selecting Guided Tour mode (that is, the mode after Event), however, 2.1Ek freezes and the only solution is turn off the scope, turn it back on, and re-initialize 2.1Ek (set date and time and re-align the scope).

I'm indebted to Mark Crossley for suggesting that 2.1Ek can, in fact, be uploaded with Autostar Uploader version A2.1 ("A2.1"). He also pointed out that Meade has the 2.1Ek ROM files in a separate ZIP file.

After purging all remnants of any installed version of Autostar Updater (both files and registry keys) from my laptop, I started with a fresh installation of Autostar Updater A2.1 ("A2.1") complete with the Autostar firmware 2.0h ("2.0h"), downloaded from Meade's web site. I downloaded the file ROMS21ek.zip (containing three files: Dbase.ROM, Autostar.ROM, and a brief readme.txt file) from Meade. I then depostited the two ROM files in the Ephemerides folder. With no other changes to A2.1's files, I then launched A2.1. It located my Autostar as expected and placed it in download mode. I then uploaded just the software to the Autostar.

With 2.3Ek loaded, I exited from A2.1 and checked my Autostar. It initialized as expected and I was able to locate the bodies included in the Dbase.ROM upload. I was able to upload some additional tours (added by dragging the icon of the appropriate .mtf file, as displayed in Windows Explorer, over the Tour button on A2.1) as well as delete some tours. Attempts to create a new asteroid entry by entering data manually into A2.1's asteroid editor repeatedly failed with a General Protection Fault (that is, A2.1 crashed).

Comments about 2.1Ek firmware:

With 2.1Ek loaded, I went through the "train motors" routine and used the scope to observe the Sun. In general, things went well except that once or twice a commanded slew in azimuth produced a slew in both azimuth and altitude at the same time. What produces this problem is not clear but it seems to happen when slewing is a multiple of the sidereal slew rate (as opposed to x degrees per minute) or after pressing 1 through 4 for the slew rate. Pressing 5 or higher and attempting to slew in one axis doesn't seem to precipitate the two-axis slewing.

I also encountered "snap back slewing" on occasion. Specifically, the scope is commanded to slew as needed to improve the view of some object. After a brief pause, the scope then slews back to close to its previous pointing *without command input*. In effect, the scope snaps back to close to its last position. This problem appears only after small movements and not after a gross change in pointing. For example, slewing from Jupiter to Aldeberan does not produce snap back slewing back to Jupiter but moving Jupiter around in the eyepiece may produce this effect. It doesn't always happen, however, so it's hard to determine a probable cause.

In general I haven't encountered the "creep after beep" problem, where the scope slews, uncommanded, to some point after the Autostar beeps, indicating it's finished slewing to a new object. I tested two tours. One supplied by Meade (Tonight's Best) and one a third party tour (Tonight's Jewels, written by Mark Crossley and obtained from his Astro & ETX web site). I went through about seven or eight objects in the first tour and then moved to the second tour. In this tour, the MODE button is used to shift from one object to the next. Once an object is selected, line 2 of the display shows a crawl of data suchas magnitude, object type, and possibly a comment. I stepped through about three or four objects on this tour and then attempted to exit the tour by pressing the MODE button repeatedly. I left the tour but the data from the last object continued to crawl on line 2. This problem was seen before when loading 2.1Ek with A2.3. I did run part of Tonight's Jewels briefly and was able to exit successfully then. It's unclear what the cause of this problem is, either [NB: Mark Crossley did report encountering a problem with text at the end of a tour when the tour is used by 2.3Ek; this may be the same problem he referred to].

So long as the uncommanded slew and the snap back slew don't happen often, 2.1Ek is certainly usable when loaded by A2.1. It's not "rock solid" and I don't recommend uploading it unless the current firmware in an Autostar is causing a great deal of problems. For now, "if it ain't broke, don't fix it" should be the rule for deciding whether or not to install 2.3Ek with A2.1.


After writing the above I decided to put 2.1Ek to a tough test. At around 2130 UTC 25 Jan., I set up my scope and walked through a two star alignment, that is, let the scope select two stars and said they were centered by the scope, even though, of course, they weren't even visible. The only point of certainty is that the scope, in the home position, was pointed due north (I have a very convenient landmark for where I set up the scope) with reasonable accuracy. I then tried to find Venus.

Sunset was about 40 minutes away, at 2211 UTC, but the sky was still very blue. Using the scope's estimate of Venus' position, I let the scope slew around to where it though Venus was. Looking in the finder (8x25) Venus was about 2-3 degrees above the finder's horizontal crosshair but centered on the vertical crosshair. I slewed the scope up and there was Venus in my 12mm Lanthanum eyepiece! The Autostar tracked it well considering there was enough breeze to shake the scope significantly.

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Copyright ©1999-2001 Michael L. Weasner / etx@me.com
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