HUNTER Specification
====================

Physical
--------

-  **Construction:** Diecast aluminium alloy.
-  **Size:** 216mm x 156mm x 32mm.
-  **Weight:** (including batteries) 1150 grammes.
-  **Sealing:** Waterproof against accidental immersion.
-  **Straps:** Wrist strap on either side.

Facia
-----

-  **Screen:** 240 x 64 dot full graphic liquid crystal display with
   keyboard-controlled contrast.
-  **Keyboard:** 58 keys arranged in four rows of 15. Qwerty layout with
   function and control keys. Fully waterproof sealed rubber keys.

Programming
-----------

-  **Built-in language:** Extended basic interpreter.
-  **File handler:** CP/M compatible software environment allows loading
   of meny popular programs.
-  **Storage:** Programs and data stored indefinitely in battery
   supported memory. Operating system stored in firmware, occupying no
   RAM space.
-  **Screen handling (text mode):** The actual screen of eight 40
   character lines forms a window on a larger virtual screen. The window
   is controlled with the cursor keys.
-  **Screen handling (graphics mode):** Both text and graphics
   information are displayed together. There are five selectable
   character sizes giving facilities for elegant, professional screen
   formatting.
-  **Keyboard:** All keys re-allocatable in software.

Communications
--------------

-  **Type:** RS-232/V24 serily software controlled.

-  **Baud rate:** Up to 4800 baud asynchronous.

-  **Protocols:** Standard 'invisible' protocols for flow control and
   security are transparent to user programs.

   Formats provided include:

   -  none/simple 'TTY' communication
   -  XON/XOFF for mini and main frame computer systems
   -  ETX/ACK for many popular printers
   -  ACK/NACK for secure telephone communication
   -  Systime, with BCC error checking
   -  2780 fully synchronous implementation

-  **Handshaking:** RTS, CTS, DTR, DSR, RT, CD, all selectable by
   software.

Graphics
--------

Full addressing of all 240 X 64 dots. Software support for lines, boxes,
circles and points.

Sound
-----

Fully programmable for 4 octave range note and duration.

Character Sets
--------------

Five different sized charactersets selectable from Basic. Reverse video
characters supported for all sets. True descenders on larger sizes.

Memory
------

-  **Type:** CMOS low power semiconductor RAM.
-  **Retention:** Battery support with soldered in Ni/Cd backup.
-  **Capacity:** Available in RAM size options of 80k byte, 144k byte
   and 208k byte. Operating system utilises 8k byte of this memory.
-  **Firmware:** Built-in operating system including file manager, Basic
   interpreter and disk emulator.
-  **Upgrading:** RAM memory can be upgraded on return to factory to
   larger size.

Real Time Clock
---------------

-  **Type:** Software accessible time of day and calendar clock. Totally
   independent of microprocessor.
-  **Accuracy:** 200ppm worst case, typically 2 sec per day.
-  **Integrity:** Non volatile, battery backed.

Microprocessor
--------------

-  **Type:** NSC800-4
-  **Software:** Executes the Z-80 instruction set (8080 super set); can
   run standard CP/M compatible programs.
-  **Cycle time:** 250ns (4MHz)

Batteries
---------

-  **Main:** Four 'AA' cells, Ni/Cd rechargeable for daily use. Mallory
   MN1500 for long shelf life and reliability.

   Typical operating lifetime (software dependant) 14h (Ni/Cd) 45h
   alkaline.

-  **Secondary:** Built-in Ni/Cd charged from main cells when operating.
   Life 50h when main batteries are discharged.