Batteries¶

HUNTER is battery powered. It runs for a long time on a set of standard ‘AA’ size cells obtainable anywhere.

A second rechargeable battery is permanently built into HUNTER so data is not lost even if the main batteries are removed. This battery should never need to be replaced.

Battery Installation¶

The batteries are spring-loaded to make contact and retained by a threaded plug. When installing batteries, follow this procedure :-

ONLY USE A COIN in the battery plug. Screwdrivers, etc., will damage the slot and HUNTER’S appearance.
Feed in the cells, positive inwards. Don’t drop the ‘AA’ cells in vertically - they can be damaged. Instead, slope HUNTER slightly.
Take the battery plug and, with finger pressure only, press into the battery compartment and turn.
Only when the thread is started, use a coin to screw the plug home.

The battery plug should stand about 2mm proud from the case wall.

Note

Clockwise inserts the plug, anti-clockwise removes the plug

Main Battery - Primary¶

We strongly recommend the use of Alkaline-Manganese batteries similiar to Mallory MN1500.

We do not recommend the use of cheaper zinc-carbon cells for routine operation, since these can suffer electrolyte leakage, have shorter lives and can introduce technical problems.

Alkaline cells will produce approximately 45 hours of HUNTER use when running a typical application program, and almost indefinite storage life. There is no need to remove cells from HUNTER during storage or shipment but remember that capacity will reduce with time.

Battery - Rechargable¶

Only Nickel-Cadmium (Ni-Cd) cells are to be used. Under no circumstances must any other type of rechargeable cell be installed. We recommend Berec type NCC50 cells of 500 mAH capacity.

Low Battery Warning¶

HUNTER is designed to provide adequate warning of impending battery failure and will protect user’s data, even in the worst situations.

When the HUNTER’s batteries become low, HUNTER will give warnings to the user. Since it is usually essential that all data and programs are secured, it is recommended that HUNTER is switched off as soon as practicable and the batteries either replaced with a fresh set or, if rechargeables are fitted, put on charge.

Low Battery warnings are repeated as follows:

every 5 seconds if the HUNTER Is switched on, but quiescent.
after every keyboard key depression.
every 0.5 seconds if characters are being received on the RS-232 port.

If ten consecutive warnings are ignored, HUNTER automatically switches off. When this occurs, HUNTER is automatically in CONT mode. This means that when power is restored, program execution will continue from precisely where it was prior to the interruption.

HUNTER has two screen modes, text and graphic (see Screen). Battery low warning is slightly different in the two modes:

Text Mode

When a low battery is detected, the top line of the screen displays:
```
* WARNING BATTERIES ARE LOW *
```
HUNTER beeps twice and then the original text is restored until the next warning.

The text screen contents are preserved and not affected by the warnings. Following power restoration, the screen is restored to its pre-warning state.
Graphics Mode

When a low battery is detected, the top line of the screen displays:
```
* WARNING BATTERIES ARE LOW *
```
in reverse video and using the smallest character set (CHAR0). This message stays on the screen between battery warnings. HUNTER also bleeps twice. The warning message destructively overwrites the top line of the screen, the contents of which are lost and must be restored by the user’s program.

If an attempt is made to use HUNTER without replacing or recharging the batteries. Battery Low warning is displayed and HUNTER immediately turns off again. It is worth commenting that flat batteries can partially recover after being switched off such that operation could continue for a short period. It is not recommended that this should be done in practise, particularly with rechargeable batteries which could then become totally exhausted. In the case of Ni-Cd batteries, this can lead to permanent damage to the cells.

Power Save¶

An automatic power conservation system has been incorporated into HUNTER, enabling the power to be removed from circuits when they are not in use.

Usually, the computer will enter power save mode whenever it is awaiting a keyboard entry. However, a few programs defeat this facility by not using standard CP/M console calls and have a correspondingly higher overall power consumption. Please consult Husky Computers for advice in specific cases.

Battery Charging¶

HUNTER is optionally available with rechargeable cells and a mains (line) powered charger.

This arrangement allows cells to be recharged in HUNTER, and for alkaline cells to be quickly substituted if the user forgets to recharge!

Danger

But BE CAREFUL - NEVER connect the charger when alkaline batteries are installed. They will NOT re-charge. Instead, they may explode, jam in the battery tube or leak corrosive chemicals.

See Battery Charger for further information regarding the use of HUNTER’S battery charger.

Continuous Connection¶

HUNTER can be powered permanently from the charger by simply leaving the unit connected. In this mode, the rechargeable cells will be kept ‘topped up’ by the charger despite the continuous current drain. Of course, a fully discharged battery will take longer to recover than if HUNTER is powered down.

Auto Timeout¶

To conserve battery life, HUNTER will automatically switch off after a period of inactivity. A warning bleep is emitted every 2.1/2 minutes to remind the user that HUNTER is turned on. This timeout does not operate in Terminal Emulation. The timeout value can be modified using POWER n in Basic and has a default value of 5 minutes.