The GRINNELL TV controls

The main 3x3 block of controls reading left to right and top to bottom have the following functions:

1.

AVERAGE - Recursively filters on-target integrations. On-target integrations are selected by the INTEGRATION rotary switch.

2.

T-INT - ON-target summation of 2**n frames. Selected via the INTEGRATION rotary switch.

3.

DIRECT - Real time digitisation at normal frame rates.

4.

FILL - Fills in the alternate lines of a stationary (FROZEN) picture. Considerably improves the appearance of faint, extended objects.

5.

FREEZE - Freezes the current picture.

6.

HARDCOPY - Put up full screen crosswire.

7.

OVERLAY-ONE - Enables/disables the first graphics overlay plane (i.e. the border, the orientation and the scale).

8.

OVERLAY-TWO - Enables/disables the second graphics overlay plane (i.e. the integration, tau, background and contrast information)

The three rotary switches below the panel buttons act as follows

INTEGRATION - The absolute position of this switch determines the number of frames of integration.

BACKGROUND - Makes the background blacker or whiter. There is no absolute position, the effect is determined by the direction and number of steps moved.

CONTRAST - As for the BACKGROUND switch but it controls the contrast i.e. softens or enhances.

Off to the left of the rotary switches are three more push buttons labelled MENU, SELECT and RESET. Pressing the MENU button will freeze the image and cause page 1 of a 2-page image processing menu to be displayed. A cursor is also displayed and may be positioned on the menu by multiple depressions of the SELECT button. The joystick may be used instead of the SELECT key for menu selection if preferred. The joystick controller box also contains the buttons to enable and disable the movement of any displayed cursor. Press the ENTER button on the joystick controller to enter the menu selection. The functions available from the menu are described in the next Section. The RESET button causes a complete reset of the system - all overlays etc will be lost.