GB2158667A - Apparatus for playing electronic games - Google Patents

Abstract

In an electronic game, the position of a joystick as determined by a plurality of switches (32) and the operation of a fire button is encoded in digital form by an encoder (34). A pulse position modulator (36) enables the digital signal to be transmitted through an infra-red link (16) to the game computer where the signal is demodulated by a pulse position demodulator (48). A key decoder (49) decodes the digital information with the aid of an address decode circuit (42) and the information regarding the position of the joystick and whether or not the fire button is operated is supplied to the computer (10) through a buffer (50). <IMAGE>

Description

SPECIFICATION Improvements in apparatus for playing electronic games The present invention relates to apparatus for playing electronic games.

More particularly, the invention relates to computer games in which there is an electro-magnetic link between a remote joystick type keyboard and a computer.

In one particular type of electronic game the joystick has a plurality of directions which it can be move to and from a neutral central position, typically eight, and has at least one "fire" button to enable a "target" in the electronic game to be fired at.

One known type of transmitter associated with such a joystick, which enables information regarding the position of the joystick to be transmitted to the computer via the electro-magnetic link which is preferably an infra-red link, consists of a custom built hand held controller, containing the transmitter circuits including the directions switches and the one or more fire buttons.

This known type of transmitter circuit has the disadvantage that it is only possible to transmit a single closure of a switch at one time. In a fast moving electronic game, this is clearly a disadvantage, since ideally one needs both to position one's attacking craft and fire a missile at the target or invading craft at one and the same time.

It is therefore an object of the present invention to overcome partially or wholly the above referred to disadvantage.

According to the present invention there is provided in an electronic game: means for encoding in digital form, information relating to the operation of one or more of a plurality of switches; means for transmitting this information; means for receiving the transmitted information; means for decoding the received information; and means for transferring it to a computer in control of the electronic game, whereby the computer simultaneously receives information regarding the position of one or more of a plurality of switches.

Preferably, these switches are associated with a joystick and represent one of eight positions as well as a fire button. The information is preferably transmitted by means of an infra-red link.

Preferably the process of encoding in digital form involves detecting which switch or switches of the plurality of switches has been operated and generating a constant current for a duration which is equal to the digital value of the selected switch or the total digital value of two or more such selected switches out of the plurality of switches. This encoded signal is transmitted via the infra-red link.

At the receiver end, the binary counter and an associated latch circuit are preferably provided for decoding the transmitted signal and determining which switches have been operated, so that this information can be fed to the computer.

The present invention will now be described in greater detail by way of example with reference to the accompanying drawings, wherein: Figure 1 is a general block diagram of a transmitter and a receiver associates with a computer, for an apparatus for playing electronic games; Figure 2 is a perspective view of one type of joystick used in playing the electronic game with the apparatus shown in Figure 1; Figure 3A is a more detailed circuit diagram of the transmitter shown in Figure 1; Figure 3B is a series of waveforms to explain the operation of the transmitter circuit shown in Figure 3A; Figure 4A is a more detailed circuit diagram of the receiver shown in Figure 1; and Figure 4B is a series of waveforms to explain the operation of the receiver cirouit shown in Figure 4A.

Referring first to Figure 1, the apparatus for playing an electronic game includes a host computer 10, transmitter 12, receiver 14, and an infra-red link 16.

The transmitter 12 is associated with the joystick 20 of the apparatus shown in greater detail in Figure 2. The joystick 20 comprises a vertical rod 22, a knob 24 at the upper end thereof, and a pair of "fire" buttons 25 and 26. The two fire buttons 25 and 26 are provided so that the joystick 20 can be operated by both right and left handed operators, the buttons 25 and 26 being operated with the thumb of the hand controlling the joystick. The lower end of the joystick is pivoted (not shown), so that by operating the knob 24 it can be moved from the neutral position (as shown) along any one of the channel slots 28a to 28h.

The transmitter is provided with its own battery power supply 30. The joystick thus has eight positions into which it can be moved from the neutral central position, each position into which it can be moved having an associated mechanical or electronic switch which is closed by the joystick to indicate that the joystick has been moved in that direction. In addition there are two mechanical or electronic switches associated with respective fire buttons 25 and 26 provided on the knob 24 of the joystick. Block 32 diagrammatically represents all these switches.

The transmitter 12 further comprises a switch encoder 34, a pulse position modulator 36, a pulse amplifier 38 and an infra-red transmitting diode 39. The battery power supply 30 provides a D.C. voltage supply to the switch encoder 34, the pulse position modulator 36 and the pulse amplifier 38. The switch encoder 34 detects which swich, or in the case where the joystick is moved into one position and a "fire" button simultaneously depressed - which switches, have been operated and encodes this information in digital form. The resulting pulse code is modulated by the pulse position modulator 36, so that all the relevant information can be transmitted via the infra-red link 16 by means of the pulse amplifier 38 and infra-red transmitting diode 39.

The receiver 14 comprises a power supply 40, an address decoder 42, an infra-red detector 44, a preamplifer 46, a pulse position demodulator 48, a key decoder 49 and a buffer 50. The address decoder 42 and the buffer 50 are interfaced with the host computer 10.

Referring now to Figure 3A, the switch encoder 34 comprises a constant current binary generator which provides a constant current for the period of the binary count input thereinto by means of the five switches 32a, 32b, 32c, 32d and 32e which respectively represent left, right, up, down and fire on the joystick 20, one end of the switches being connected to the binary inputs of 2, 4, 8, 16 and 32 respectively, whilst the other ends thereof are earthed. The binary input 1 of the constant current binary generator is permanently earthed. By placing the joystick 20 in the slots 28a to 28h the following switch 32 are operated.

Slot Switches 28a 32b 28b 32b & 32d 28c 32d 28d 32a & 32d 28e 32a 28f 32a & 32c 289 32c 28h 32b & 32c.

The switch 32e is operated by either of the fire buttons 25 and 26.

The pulse position modulator 36 comprises a clock pulse generator 52, a comparator 54, a squaring circuit 56, a monostable circuit 58 having an unstable duration of 800,ups, capacitors C1 and C2, resistors R1, R2 and R3, a diode D, a transistor 0, and an inventer I. The output from the constant current binary counter 34 is applied toone input of the comparator 54. The other input of the comparator receives a reference voltage derived from a potentiometer comprising the resistors R1 and R2. The collector-emitter path of the transistor Q is connected between the output of the constant current binary counter 34 and earth, whilst its base is connected to the output of the clock pulse generator 52.The clock pulse generator 52 can be disabled both by the output from the comparator 54 and also the output from the monostable circuit 58. The capacitator C2 and resistor R3 constitute a differentiating circuit and due to the presence of the diode D only the trailing edge of the output waveform tl from the comparator is differentiated. The squaring circuit 56 provides a negative going pulse which is applied to both the monostable circuit 58 to trigger it and also to the pulse amplifier 38.

Referring also to the waveforms shown in Figure 3B, the encoding operation is started by the output of a trigger pulse from the clock pulse generator. This pulse is applied to the base electrode of the transistor 0 which causes it to discharge the capacitor C1 and also to the pulse amplified 38 through the inverter I, the resultant waveform being shown by waveform (z). During the next period, a constant current flows for a given time between 10 and 630us according to which switch or switches have been operated on the joystick 20.For example if the joystick has been placed in slot 28f and the fire button 26 simultaneously operated, the binary count provided by the switches 32a, 32c and 32e is 42 which will produce a constant current output from the generator 32, for the appropriate period, e.g. 430 > s. The constant current output for the appropriate period is passed through the comparator 54 to produce the waveform tl as shown by waveform (y) in Figure 3B, having the appropriate length. The leading edge of the waveform tl disables the clock pulse generator 52 which renders the transistor 0 non-conductive to enable the capacitor C1 to be recharged from the output of the binary generator 34.

The trailing edge of waveform t1 is differentiated by means of the differentiator circuit comprising the capacitor C2 and resistor R3 and the squaring circuit 56 produces a negative going pulse as shown in waveform (x). Thus negative going pulse is applied to both the pulse amplified 38 and the monostable circuit 58 to trigger it to its unstable state. In this state the monostable provides a negative output pulse of 800'is as shown in waveform (w) so as to keep the clock pulse generator 52 disabled. At the end of this 800,a period, the monostable triggers back to its stable state which allows the clock pulse generator 52 to generate another trigger pulse. The output waveform as output by the pulse amplifier 38 is shown in waveform (v) which effectively consists of the trigger pulse from waveform (z), the encoded period tl, the pulse of the squaring circuit from waveform (x) and the 800s delay before the next trigger pulse.

Referring now to Figure 4A, the pulse position demodulator 48 and key decoder 49 comprise a 750ps re-triggerable monostable circuit 60, a 6-bit binary counter 62, a 5-bit latch circuit 64, a clock pulse generator 66, a pair of NAND gates 68 and 70, and an inverter 72. The NAND gate 68 receives inputs direct from the pre-amplifier 46 and from the output of re-triggerable monostable circuit 60. The NAND gate 70 receives inputs direct from the pre-amplifier 46 and from the output of inverter 72 which inverts the output waveform from the re-triggerable monostable 60. The 6-bit binary counter 62 receives an input from the output of the NAND gate and also 100 KHz pulses from the clock pulse generator 66. The 5-bit latch circuit 64 receives the 2, 4, 8, 16 and 32 binary output from the binary counter 64, and also a latch input from the NAND gate 70.

The waveform (v) transmitted by means of the infra- red link 16 is output from the pre-amplified 46 as waveform (u) in Figure 4B. During the period of the tl waveform the output from the re-triggerable monostable circuit 60 is held at the high level. However, during the following 800 > s period the output from the monostable circuit 60 falls to the low level and is re-triggered back to the high level by means of the trailing edge of the trigger pulse as shown in waveform (t) of Figure 4B.

The NAND gate 68 which receives both the original waveform (u) and the output from the monostable circuit 60 as hsown in waveform (t), provides a negative going reset pulse when both waveforms (u) and (t) are at the low level, as shown in waveform (s). This reset signal resets the binary counter 62, which then starts to count from zero, the pulses output from the clock pulse generator 66.

On the other hand because the invertor 72 inverts the output from the monostable circuit 60, the NAND circuit 70 does not provide a negative going latch signal until coincidence is detected with the signal output from the squaring circuit 56 shown in waveform (x). This latch signal is shown in waveform (r), and it latches the 5-bit latch circuit 64 at that instant so that the binary count reached by the binary counter 62 is recorded.

Thus the decoded output from the latch circuit 64 provides the appropriate outputs on its five output leads to represent those switches 32 which were operated. These are fed to the buffer 50 which together with the associated address decoder 42 both interfaced with the computer 10, supply the switch information to the host computer.

The above described transmitter and receiver associated with a computer for playing electronic games has the advantage over known arrangements of providing a much faster game in that it is possible to both position one's own craft and fire a missile at the enemy or an invading craft at one and the same time, due to the novel switch position encoding and decoding process.

Whilst the above described embodiment has five switches associated with the joystick and fire buttons, it will be appreciated that any number of switches may be provided according to the particular application required for any given electronic game.

Claims (8)

1. In an electronic game the combination of: means for encoding in digital form information relating to the operation of one or more of a plurality of switches; means for transmitting this information: means for receiving the transmitted information; means for decoding the received information; and means for transferring it to a computer in control of the electronic game, whereby the computer simultaneously receives information regarding the position of one or more of the plurality of switches.

2. The combination according to claim 1, wherein the plurality of switches are associated with a joystick and represent a plurality of positions.

3. The combination according to claim 2, wherein eight equi-spaced directional positions are represented by said plurality of switches as well as at least one fire button.

4. The combination according to any one of the preceding claims, wherein the information represented by the operated switch or switches, having been encoded in digital form is transmitted to the receiver means via an infra-red link.

5. The combination according to any one of the preceding claims, wherein in order to ascertain which switch or switches of the plurality of switches have been operated, means are provided to detect the operation thereof and to generate a constant current for a duration which is equal to the digital value of the selected switch or the total digital value of two or more such selected switches out of the plurality of switches.

6. The combination according to claim 5, wherein the encoding means includes a pulse position modulator comprising a clock pulse generator, a comparator, a squaring circuit and a monostable circuit, in order to provide a synchronized waveform, a part of which is representative of the encoded digital signal.

7. The combination according to any one of the preceding claims, wherein the receiver means includes a binary counter and latch circuit for decoding the transmitted signal and for determining which of the switches of the plurality of switches has been operated, so that this information can be fed to the computer.

8. In an electronic game the combination constructed substantially as herein described with reference to and as illustrated in the accompanying drawings.