Version V Firmware Upgrade for the GTOCP3 -
Required for Astro-Physics Command Center (APCC)

The EEPROM of the GTOCP3 must be updated to version V firmware in order to download and use our Astro-Physics Command Center (APCC) software. It contains many new commands needed for the advanced features of APCC, including custom absolute tracking rates implemented in arc seconds per hour and new meridian delay commands and functions to name a few.

Determine your Current ROM Chip Version

There are several ways to check the version letter and date of the microprocessor ROM chip to see if you already have an V version chip.

How does the "V" Chip Differ From the Chip I Currently Have?

Refer to Revisions to ROM chip of the GTOCP3 Control Box (PDF).


Please refer to the information below to determine the pricing for your chip upgrade.

All mounts with R, S, S1, T, and U chips
The final version of the V chip will be provided to you free of charge along with an extraction tool and instructions for installation. We will notify you when the chips are ready to send so that we may confirm your shipping address.

All orders shipped since July 22, 2014
The "V" version chip was/is already included with these mounts.

All mounts with GTOCP3 control boxes that are not included in the categories above.
We are not currently accepting new orders yet until we are further along in our upgrade process.

Installation Options

You may choose to install the chip yourself using these instructions or send the control box to Astro-Physics. There is an additional installation charge of $45 plus return shipping.

Important Considerations if you are upgrading from "Q" or earlier version.

If your previous ROM chip was version Q or earlier, you MUST perform a full initialization on your first power-up, and you will also need to redo the mounts PEM (Periodic Error Memory). To accommodate the added features of these newer chips, the location in the GTOCP3s non-volatile memory where time, location, gear angle and PE information is permanently stored has been changed. Your previously stored data will no longer be usable. The new information you enter now, however, will be remembered going forward.

Initialization: If you use the keypad in your first session, follow the instructions in the Keypad Manual as if you are setting up for your first session. You will not have to setup your location data or time since that information is stored in the keypad.

If you control your mount with a PC in your first session (i.e. with the ASCOM Driver, APCC, PulseGuide or any other computer control), be sure that the options are selected to send all of the time, date, GMT offset and location data to the mount. For your first time using the new ROM chip your computer software MUST give the servo a full initialization. You will also need to reestablish pointing and orientation by resuming from one of the AP pre-defined park positions or by performing a Sync on a star. Note: a Re-Calibrate is not sufficient.

PEM (Periodic Error Memory): You will need to redo your PEM. Since the gear angle information is lost, the PE data that you have stored will no longer be in sync with the worm gear, so simply saving it to your computer via PEMPro and reloading it will not work. Once new PEM data is stored with the correct gear angle association, it will be remembered going forward.

Order Information

We are not accepting new orders for "V" chips or GTOCP3 control boxes at the present time. However, we are sending "V" chips as free upgrades to customers who have R, S, S1, T or U chips currently installed. We are contacting customers in groups. If you have one of the original chips listed and have not been contacted yet, please be patient. If you purchased a mount from a dealer or another individual and have not yet registered, fill out the Mount Registration Form and either e-mail, fax or send it in. We will enter the change of ownership information into our database. If you have one of the chips mentioned above, we will contact you.

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This page was last modified: September 22, 2014

Astro-Physics, Inc.
11250 Forest Hills Road, Machesney Park, IL  61115, U.S.A.
Phone: 815-282-1513   Fax: 815-282-9847