Paul and all GTO users,
Here is an updated version of the changes made thus far to the firmware in
the keypad and the chip located in the servo box. Charles is working on a
few enhancements and minor fixes in the keypad software which will be v2.6
when finished.

If you want to upgrade to v2.5, you have two options. If you can't wait,
send the keypad into Astro-Physics and we will reprogram it. Since we have a
new version in the wings, I recommend that you wait for our internet
download from our web site which we are planning to have in October. In
order to accomplish the download, you will need a new chip in your servo box
(we will probably charge about $30 to cover the cost of the chip, extraction
tool needed to remove current chip and shipping). These will be available in
October also and can be easily installed by the user. Then, you will be able
to upload all future upgrades to the keypad firmware from our web site
without further costs. This will make it easy for all.

UPDATES TO KEYPAD AND SERVO DRIVE CHIP
KEYPAD REVISIONS
After 6-22-98
Fixed PEM and added timer
Fix save of Dec backlash
Complete safe zone with save
Change set site location - took negatives out, added W-E and N-S (the
minus zeros were a problem).
Fixed ADS separations
Removed "size" from object data since most objects are irregular and this
data was not loaded
Fixed RA/Dec entries involving minus 0
Activate park function
Added current position function to NEXT button at Objects Menu
Reorganized and corrected search function
Recalculated lunar position (later determined this was incorrect)

7-13-98
Corrected lunar position calculation
Change focus default setting to Low to correspond with TheSky

7-15-98
Removed Display Time/LST from Setup-2 menu
Add RA Backlash to Setup-1 menu (new function)
Moved Reticle adjustment to Setup-2

7-16-98
Add N-S-E-W button function to Cal. Menu when star choice data is
displayed
Prevent observer from using N-S-E-W directional buttons in Center Polaris
screen
Put Focus selection in #2 spot in Setup1 so that people don't accidentally
change the backlash setting which was in #2 spot

7-18-98
Fix PEM (timer was not going off consistently)

7-21-98
Increased backlash compensation for 400 & 600E mounts

7-29-98
Fixed planets menu, which used to skip #1 and begin w/# 2 (if you pressed
1 accidentally, you got gibberish). Now #1 works properly for first
selection.

8-25-98 - version 2.1
Fixed sign of declination number of Southern Hemisphere objects from +
to -. Used to show + sign when displaying RA/Dec coordinates prior to go-to
action.
Will now go to objects between 0 and -1 latitude.
Save position of common object names in Tours menu. When you go to a
common object from this menu, then press Menu, the display will return to
the screen that shows the last common object you viewed. If you go to other
objects using other menus (Search, M, etc) then return to common names menu,
the display will show the last common name object you viewed. Previously, it
returned to the beginning of the common objects list each time.
Save position of Stars/Constellation in Tours menu. When you go to a star
in a chosen constellation, then press MENU, the display screen will return
to the same constellation and screen as previous entry. Previously, it
returned to the first screen of the constellation with the alpha star.
Save position of Objects/Constellation in Tours menu. When you go to an
object in a chosen constellation, then press MENU, the display screen will
return to the same constellation and object screen as previous entry.
Previously, it returned to the first screen of the constellation with the
alpha star.

9-15-98
Corrected remainder of objects that have -00 latitude (these had +00)

11-2-98 - version 2.2
Allow user to change button rate at five additional places in the program.
Pushing "+-" button brings up screen that allows you to change button rate.
Button rate can be changed when you are in these functions: "Pick star"
screen in startup procedure, 'cal star" screen in startup procedure,
"objects menu" screen, screen that displays after you slew to an object,
RA/Dec coordinates display that is accessed by next button after you slew to
object. These are places that the user is likely to need this feature. The
screen displays "guide speed: <rate> x", rates are from .25x through 1200x.
Toggle through the selections using Prev< and Next> buttons.

11-12-98
Reword screen that comes up when push "+ -" button. Used to display, i.e.
"guide speed: 64 x", now displays "button rate: 64x".

01-14-99 version 2.3 (actually downloaded in mid-December)
N Polar Calibration routine changed. Previously, the user had to manually
move the telescope to the next calibration star, and then the scope would
slew back to Polaris. Now, the user moves the scope manually to the first
star, then all subsequent movements are automatically slewed with keypad
controller. Each time you use the N-S-E-W buttons to center a star, then
press Menu, you recalibrate.
Two Star Calibration routine has been simplified. Probably easiest to
compare instructions to see the differences. Now the user goes to a star and
makes adjustments halfway with N-S-E-W buttons and the remaining half with
the alt-az adjusters. When the user selects Menu to exit, the mount
recalibrates and you can either go to another star or exit the program.

01-30-99 version 2.4
Revised park function to include Park 1, Park 2 and Park 3. When you
select one of these park positions, the mount auto-slews to one of the
following locations: Park 1 - the scope will be level and pointing north.
Park 2 - the scope will be level and pointing east. Park 3 - the scope will
point to the pole. You can use the Park 1 position (also called reference
park) with a bubble level to polar align your telescope in the daytime or
when you can't see Polaris.

06-02-99 version 2.5
Park functions work correctly in Southern Hemisphere.
Improved declination backlash range for 400GTO.
Prevent user from bypassing Startup routine in location selection and Cal.
Menu screens. In previous versions, it was possible to press MENU and escape
the Startup, however then the mount was not calibrated.
If a user still manages to bypass the Startup routine at the Cal. Star
selection screen by pressing MENU, the keypad will send the data for the
reference park position (see the manual for discussion of this postion).

SERVO DRIVE BOX REVISIONS - Chip Program
7-9-98
Solved 80% of problem - if slew with buttons to various areas of sky, the
mount gets lost when asked to slew to object. Just two areas remain that are
below mount in areas not likely to slew to.

7-16-98
Can slew anywhere in sky with buttons and mount knows where it is (used to
get lost if you were pushing N-S-E-W buttons to guide across the meridian or
when scope was below mount).
Made adjustments to allow correct movement (motors and slewing direction)
in southern hemisphere

7-17-98
Fixed PEM (was not recording properly)

10-30-98
If motor stalls more than 1 second, the drive will shut off. This is a
safety feature to prevent motor burnout in case of severe load on the motor
due to an extreme imbalance condition or if the power to the mount has been
accidentally left on and the scope has hit a hard stop.

12-18-98
The telescope can now be placed in any of 3 park positions, the power
turned off and the keypad removed. When the power and keypad are restored,
the mount will stay parked and not resume tracking until the Resume from
Park function has been entered on the keypad.

Note: We recommend removing all power cords from the mount and/or from the
wall socket to prevent damage from direct lightening strikes.

5-13-99
Horizon check - This function is normally used from the keypad. Added it
to the chip so that people who are writing software will have access to this
command code. Commands:
:ho# means on
:hq# means off
Fix communications interrupts that caused a problem when using DigitalSky
Voice and TheSky software together. This problem occurred with version 5
of TheSky.
Provides ability to download new keypad versions from our web site. This
has been tested in simulated download, but not an actual web download. This
part of the code may need revision before finalized.

07-29-99
Initialize the COM ports twice to be sure they can establish communication
consistently.

08-09-99
Allow recalibration during PEM playback without extraneous motion.

Marjorie Christen
Astro-Physics