Screen

HUNTER has a large LCD (Liquid Crystal Display) screen. It can present up to 320 characters on 8 lines of 40 characters each, just like a small video terminal.

The character set includes upper and lower case alphabets and special characters. Additionally, a graphics display of 240x64 pixels is supported.

HUNTER'S display is designed for use in bright sunlight where other displays (the red 'LED' or green 'vacuum flourescent', for example) become invisible.

Because it works by contrast, rather than emitting its own light, it is perfectly visible no matter how bright the light is. But a word of caution: try to avoid leaving HUNTER exposed to direct sunlight for prolonged periods - the delicate chemicals in the LCD can be damaged.

The 'Cursor' shows where data entered on the keyboard will appear.

The screen is protected by an acrylic window, as strong as glass. Like glass, it can be scratched, so please take care. The window should only be cleaned with chamois or lens cleaning cloth.

HUNTER is built to last - please take care of it.

Screen Modes

The screen can be used in two ways:

  • Text mode
  • Graphics mode

Text mode provides only character support with the standard 8 lines of 40 characters displayed. Internally, there is a "virtual screen" supporting 24 lines of 80 characters. This mode can support any standard CP/M program, e.g. SuperCalc or dBase II. It can be used in this fashion due to the speed at which the LCD screen can be refreshed in this mode. This is the only mode supported for CP/M based programs.

Graphics mode will support characters of five different sizes, reverse video and full graphic capabilities. There is no "virtual screen" associated with this mode. It is only supported from Basic.

Screen Control

The text screen will support "clear" and screen addressing. The screen is addressed throughout the virtual screen, that is the addressing range is from 0 to 79 horizontally and 0 to 23 vertically.

Cursor addressing is a three character sequence sent to the screen handler. It is of the form:

Cursor addr control, x-coordinate, y-coordinate

The cursor address control if 0FH (15 dec).

The x coordinate is a number 0 - 79.

The y coordinate is a number 0 - 23.

The screen may be cleared by sending a control-A or 01H character to the screen handler.