GB2331165A - Computer mountable clock/calendar - Google Patents

Abstract

A mountable clock/calendar, a device has connectors which allow it to be connected in line in a computer data cable. It does not affect the use of the data link for other purposes. It can provide the correct time and date for the attached computer in case the computer for some reason does not have the proper date and time. Radio transmissions may be used to obtain the correct time.

Description

MOUNTABLE CLOCK/CALENDAR This invention relates to a mountable clock/calendar.

Clock/calendars for computers are well known electronic devices which continuously maintain the date and time of day when the computer is switched off. There are many examples of the use of computers and other equipment where it is important that the correct date is available to the equipment or to programmes running on the computers. It is often required also that the correct (approximately) time be available. A computer normally contains at least one 'clock but if just one this usually provides only 'ticks' at a nearly constant rate when the computer is switched on.

A computer operating system is normally responsible for keeping track of the time and date while the computer is switched on. Commonly it does this by counting the ticks and then calculating the date and time as required by reference to the number of ticks counted since some known reference date and time (such as 00:00:00 on 1 Jan 1980) and tables of days in each subsequent month. As one of its normal functions the operating system passes this time and date information to other programmes running on the computer when they request it. When the operating system is 'booted' (i.e- when it is loaded into the computer and it begins its execution) the date and time is not known to it. At this time some operation must be performed to make the correct date and time available to it. The operation may be manual or automatic. The operating system commonly converts the information into the number of ticks which would have been counted had it been running since the reference date, and stores this (large) number. It then updates this number each time it detects a clock tick.

When personal computers first became available, many types of clock/calendar circuit board were developed. They were fitted inside the computers and together with special software gave to the operating system the ability to find the time and date from these circuit boards automatically.

These circuit boards usually carried a power source such as a primary or rechargeable cell or battery. After booting it would still be the responsibility of the operating system to keep, in the same way as before, an up to date record of the time and date by reference to the computer clock ticks.

Later it became common practice to fit a clock/calendar circuit to the computer's main circuit board (motherboard) and, as a result, separate internal clock/calendar circuit boards became obsolete. Motherboards still usually carry a cell or battery or similar device to provide the power for the clock/calendar when the computer is switched off. The use of the clock/calendar remained unaltered, i.e. it was still used only to initialise the date and time kept by the operating system at the time of booting it.

Many operating systems handle dates correctly until at least the end of the year 2099. However, the operating system will commonly have no way of verifying that a date passed to it at boot time is correct. If incorrect it may then pass incorrect information to the programmes to which it provides the service.

Unfortunately, many computers manufactured even as recently as 1997 either have defective clock/calendar circuits or else 'firmware' responsible for reading the clock/calendar during the boot process may interpret the information incorrectly under certain circumstances. A further problem is that when the computer is switched off, the computer clock/calendar circuits rely on stored electrical charge and the charge can be depleted, causing the information to be lost. It is necessary to dismantle the computer to gain access to the clock/calendar or its power source to identify and repair or replace it. This is a job for a trained person because of the risks to the person and of damage to the computer. It will be a costly exercise for each computer.

Unfortunately, an incorrect date may not immediately be obvious. Even if it is obvious, the user of the computer may not notice it, he may not know what to do to correct it or he may ignore it. To use a computer without taking proper precautions to have the correct date it to risk causing serious problems if the date is of significance, as in accounting and diary programmes for example. These programmes, when they use an incorrect date and time, may do serious damage to information contained in the computer and this may be very costly to repair or even irreparable.

Other programmes, such as those that schedule regular events like backup of information out of office hours, may rely on the correct date and time to perform the operations at the right time. If they have incorrect date information, actions may be taken at inappropriate times, or not at all. Failure to be in possession of a usable backup tape could for example give rise to unexpected, unsustainable liabilities. Unless action is taken in good time, because of the large numbers of computers affected the users can expect to be inconvenienced (at least) by their computers for a considerable period as the industry struggles to cope with the demand for repairs.

THE COST FACING THE WORLD-WIDE ECONOMY IS INCALCULABLE.

A 'dongle' is a well-known device which is usually used for the protection of software from copyright infringement. It is normally inserted 'in line' into a cable which connects a computer and other equipment such as a printer by means of male and female connectors on the dongle in such a way that it does not disrupt the flow of information between the computer and the other equipment. Software which is to be protected contains portions (which are also well known) to test for the presence of the dongle and it is inoperable if the dongle is not properly attached to the computer or its cabling.

According to the present invention there is provided a mountable clock/calendar device comprising electronic components which continuously keep the date and/or the time when no power is available to the device or which are capable of finding the date and/or the time as required by some means such as by the reception of radio transmissions and which allow information in the clock/calendar device to be communicated to a computer or other equipment to which the device is externally mounted.

A specific embodiment of the invention will now be described by way of example. It is cheap to make and use. The device offers a means of avoiding the need to modify computer hardware or firmware in order to overcome problems associated with reading an incorrect date and/or time from the computer's internal clock.

The device comprises an injection moulded case of approximately 50mm by 50mm by l9mm housing two 25-pin sub-miniature connectors, male and female, and a printed circuit board. The circuit board carries a number of known components including a 35mAH lithium cell, capacitors, one or more clock/calendars, a microprocessor, non-volatile memory, voltage level convertors, dc-dc convertors, and well-known ancillary components. Preferably the circuit board carries a modem. Preferably the circuit board carries a radio receiver. Preferably the circuit board carries a means by which the microprocessor canmeasure temperature. Preferably the circuit board carries unique identification. Preferably the circuit board carries at least one optical coupler. Preferably the circuit board carries a photoelectric cell. Preferably the injection moulded casing is tamper-proof and/or tamper-evident.

Components are assembled into the device (and simultaneously interconnected) and the microprocessor is programmed all using known techniques. The microprocessor programme uses known techniques to ensure that the device responds only to signals sent by a special programme which runs on a computer, to which it will be attached via a serial port, and that it does not interfere with use of the port for other purposes.

Before use the date and time in the device are set by known techniques. It then works for at least 10 years.

Before use the device must be connected to a serial port on a computer and the special programme must be put into the computer. These operations can be carried out by a person using no special skills by following a list of instructions provided with the device. Thereafter the special programme communicates with the device automatically when the operating system is booted.

It verifies that the information in the device is correct and informs the operating system of the correct date and time.

Then it relinquishes all control of the computer.

In another embodiment of the invention the clock/calendar and other parts of the device are set and/or verified by communication with remote equipment. In another embodiment of the invention several clocks and calendars are simultaneously maintained in one device and it is provided with a means of periodically measuring temperature. It collects information about the timekeeping accuracy of the device and the computer clock under various conditions and makes small corrections.

Claims (20)

1. CLAIMS 1. A mountable clock/calendar device comprising electronic components which continuously keep the date and/or the time when no power is available to the device or which are able to find the date and/or the time as required by some means such as by the reception of radio transmissions and which allow information in the clock/calendar device to be communicated to a computer or other equipment on to which the device is externally mounted.
2. 2. A device containing electronic circuits and connectors to enable the connection or 'port' on the computer or equipment or cables to which the device is attached also to be used for another purpose, for which they may have been employed prior to the mounting of the device, without any modification being necessary to the hardware or software of the computer, cables or other equipment solely because of the connection of the device and containing a means of finding or permanently keeping the time and/or date and a means of communicating this information to other devices or equipment.
3. 3. A electronic timekeeping device containing the date and/or the time wherein corrections are made by the device itself to the date and/or the time according to the timekeeping characteristics discovered or known about the device and the conditions to which the device is known or supposed to have been subjected by reason of measurements made by it.
4. 4. A device capable of being linked to an existing computer or other equipment data link which link may be substantially unaffected by the presence of the device and which device is capable of communicating with equipment not part of the device for the purposes of finding particular information and making it available to other programmes or equipment.
5. 5. A device substantially as described herein.
6. 6. A device as in any preceding claim containing at least one continuously operating clock/calendar.
7. 7. A device as in any preceding claim containing a store of energy such as a cell, a battery or a capacitor.
8. 8. A device as in any preceding claim containing a means of replenishing energy stored in the device from power available from the attached equipment when the latter is energised.
9. 9. A device as in any preceding claim containing a means of operating from the power available from attached equipment.
10. 10. A device as in any preceding claim containing a primary cell.
11. 11. A device as in any preceding claim containing a convertor of energy such as a photoelectric or thermoelectric cell.
12. 12. A device as in any preceding claim containing a microcomputer or other programmable electronic device.
13. 13. A device as in any preceding claim containing non-volatile memory.
14. 14. A device as in any preceding claim containing a means to verify the stored information.
15. 15. A device as in any preceding claim containing a means to measure temperature.
16. 16. A device as in any preceding claim containing a dongle and/or a means of uniquely identify the device.
17. 17. A device as in any preceding claim incorporating a means of tamper detection.
18. 18. A device as in any preceding claim containing a radio receiver.
19. 19. A device as in any preceding claim containing an optical coupler.
20. 20. A device as in any preceding claim containing a modem.