JPS6350898B2 - - Google Patents
Info
- Publication number
- JPS6350898B2 JPS6350898B2 JP56184113A JP18411381A JPS6350898B2 JP S6350898 B2 JPS6350898 B2 JP S6350898B2 JP 56184113 A JP56184113 A JP 56184113A JP 18411381 A JP18411381 A JP 18411381A JP S6350898 B2 JPS6350898 B2 JP S6350898B2
- Authority
- JP
- Japan
- Prior art keywords
- node
- signal
- collision
- coupling device
- bus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000005540 biological transmission Effects 0.000 claims description 38
- 230000008878 coupling Effects 0.000 claims description 28
- 238000010168 coupling process Methods 0.000 claims description 28
- 238000005859 coupling reaction Methods 0.000 claims description 28
- 238000001514 detection method Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 7
- 230000003287 optical effect Effects 0.000 description 17
- 229920000642 polymer Polymers 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 239000013307 optical fiber Substances 0.000 description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/40—Bus networks
- H04L12/407—Bus networks with decentralised control
- H04L12/413—Bus networks with decentralised control with random access, e.g. carrier-sense multiple-access with collision detection (CSMA-CD)
Description
【発明の詳細な説明】
本発明はローカル・ネツトワークに接続された
プロセツサや端末機器等からなる複数のノードが
該ローカル・ネツトワーク上に信号を殆んど同時
に送出することにより生じるパケツト衝突時に、
該パケツトの衝突を起こしたノード列における各
ノードの位置を識別する方式に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION The present invention solves the problem of packet collisions that occur when a plurality of nodes including processors, terminal equipment, etc. connected to a local network send signals almost simultaneously onto the local network. ,
The present invention relates to a method for identifying the position of each node in a node string that caused a packet collision.
従来、ノードの位置識別はローカル・ネツトワ
ーク内に固定的に置かれた基準となるノードから
の信号によつて行なつていた。（たとえば電子通
信学会、技術報告（信学技報）交換方式SE78−
94「Reservation Ether Networkの方式設計」大
宮地1978年12月15日23〜29頁）このため該基準と
なるノードの障害時にはローカル・ネツトワーク
全体が障害となる、基準となるノードのような複
雑な装置が必要となるといつた欠点があつた。 Conventionally, the location of a node has been identified by a signal from a reference node fixedly placed within a local network. (For example, Institute of Electronics and Communication Engineers, Technical Report (IEICE Technical Report) Exchange System SE78-
94 "Method Design of Reservation Ether Network" Omiyaji, December 15, 1978, pp. 23-29) Therefore, if the reference node fails, the entire local network will fail. The disadvantage was that it required specialized equipment.
本発明はこれらの欠点を除去するため、衝突し
た各ノードが受信した他ノードからの信号の方向
から該他ノードの位置を検出することにより、衝
突ノード列における両端のノードの識別を可能と
したもので、以下図面について詳細に説明する。 In order to eliminate these drawbacks, the present invention makes it possible to identify nodes at both ends of a colliding node string by detecting the position of the other node from the direction of the signal received by each colliding node from the other node. The drawings will be described in detail below.
第１図は本発明の実施例の概略図である。１は
光フアイバを用いたバス構造の伝送路、２−１〜
２−３は結合装置、３−１〜３−３はプロセツサ
及び端末機器等から構成されるノード、４−１，
４−２は終端装置である。第２図は結合装置にお
ける光信号の流れを示す概念図である。１は伝送
路、５−１は左方向から、５−２は右方向からの
信号受信用導波路、６−１は右方向へ、６−２は
左方向への信号送信用導波路、７は分岐集線装置
である。信号受信用導波路５−１，５−２の各々
に光受信器を接続することにより、受信信号の方
向識別（該受信信号をどちらの方向から受信した
か、即ち発信ノードが受信ノードの左右どちらの
側に存在するかの識別）が可能となる。複数のノ
ードが伝送路に殆んど同時に送信を行なうことに
よつて該複数のノードの中に信号の衝突を起こす
ノード（衝突ノード）が生ずる場合に、第２図の
構成の結合装置では自ノードの送信した光信号が
自らの受信用回路によつて検出されることはな
く、送信中に何らかの信号を受信すれば衝突を起
こしたノードが存在すると判断できる。このと
き、信号を右側からしか受信しなかつたノードは
衝突ノードの存在するノード列（衝突ノード列）
の左端に位置し、左側からしか受信しなかつたノ
ードは衝突ノード列の右端に位置し、両側から受
信したノードは少なくとも２つの衝突ノードの間
に位置すると判断できる。 FIG. 1 is a schematic diagram of an embodiment of the invention. 1 is a transmission line with a bus structure using optical fiber, 2-1~
2-3 is a coupling device, 3-1 to 3-3 are nodes consisting of processors, terminal equipment, etc., 4-1,
4-2 is a terminal device. FIG. 2 is a conceptual diagram showing the flow of optical signals in the coupling device. 1 is a transmission path, 5-1 is a waveguide for receiving signals from the left direction, 5-2 is a waveguide for receiving signals from the right direction, 6-1 is a waveguide for transmitting signals to the right direction, 6-2 is a waveguide for transmitting signals to the left direction, 7 is a branch concentrator. By connecting an optical receiver to each of the signal receiving waveguides 5-1 and 5-2, it is possible to identify the direction of the received signal (which direction the received signal was received from, that is, whether the transmitting node is on the left or right side of the receiving node). This makes it possible to identify which side the object is on. When a plurality of nodes send signals on the transmission path almost simultaneously, and some nodes cause signal collisions (colliding nodes), the coupling device with the configuration shown in FIG. The optical signal transmitted by a node is not detected by its own receiving circuit, and if any signal is received during transmission, it can be determined that there is a node that has caused a collision. At this time, the node that received the signal only from the right side is the node string where the collision node exists (collision node string)
It can be determined that a node located at the left end of the colliding node that receives data only from the left side is located at the right end of the colliding node string, and a node that receives data from both sides is located between at least two colliding nodes.
第３図は右方向、左方向それぞれ独立の伝送路
を用いた本発明の他の実施例における結合装置の
光信号の流れを示したものである。１−１は右方
向、１−２は左方向への伝送路、５−１は左方向
から、５−２は右方向からの信号受信用導波路、
６−１は右方向へ、６−２は左方向への信号送信
用導波路、７は分岐集線装置である。この場合も
第２図と同様の動作を行なうため、送信中に受信
した信号の受信方向により、衝突を起こしたノー
ドが各々自ノードの衝突ノード列における位置
（左端、右端、他ノードの間）を識別可能である。 FIG. 3 shows the flow of optical signals in a coupling device in another embodiment of the present invention, which uses independent transmission paths in the right and left directions. 1-1 is a transmission path to the right, 1-2 is a transmission path to the left, 5-1 is a waveguide for receiving signals from the left, and 5-2 is a waveguide for receiving signals from the right.
6-1 is a waveguide for transmitting signals to the right, 6-2 is a waveguide for transmitting signals to the left, and 7 is a branch concentrator. In this case as well, the same operation as in Figure 2 is performed, so depending on the reception direction of the signal received during transmission, each node that caused a collision determines its position in the colliding node string (left end, right end, between other nodes). can be identified.
第４図は高分子光導波路を用いた第３図の結合
装置の具体的な実現例である。１−１，１−２は
光フアイバを用いた伝送路、５−１，５−２，６
−１，６−２，８−１，８−２，９−１〜９−４
は高分子光導波路、１０−１，１０−２は光受信
装置でフオト・ダイオードを用いる。１１−１，
１１−２は光送信装置でレーザ・ダイオード又は
発光ダイオードを用いる。１２−１〜１２−４は
ノードと結合装置との接続ケーブル、１３は結合
装置筐体、１４−１〜１４−４は結合装置と接続
ケーブルとの接続装置、１５−１，１５−２は伝
送路と結合装置との接続装置である。 FIG. 4 is a concrete implementation example of the coupling device of FIG. 3 using a polymer optical waveguide. 1-1, 1-2 are transmission lines using optical fibers, 5-1, 5-2, 6
-1, 6-2, 8-1, 8-2, 9-1 to 9-4
1 is a polymer optical waveguide, and 10-1 and 10-2 are optical receivers using photo diodes. 11-1,
11-2 is an optical transmitter that uses a laser diode or a light emitting diode. 12-1 to 12-4 are connection cables between the nodes and the coupling device, 13 is a coupling device housing, 14-1 to 14-4 are connection devices between the coupling device and the connection cable, and 15-1 and 15-2 are This is a connection device between a transmission line and a coupling device.
左方からの光信号は伝送路１−１から高分子光
導波路９−１，５−１経由で光受信装置１０−１
で検出され、電気信号として接続ケーブル１２−
１によつてノードへ伝えられる。右方向からの信
号は伝送路１−２から導波路９−４，５−２経由
で光受信装置１０−２で検出され、電気信号とし
て接続ケーブル１２−４によつてノードへ伝えら
れる。よつて、ノードでは接続ケーブル１２−
１，１２−２上の電気信号を監視することによ
り、現在受信中の信号が自ノードより右側のノー
ドから送信したものか、左側のノードから送信し
たものか、あるいは両方向であるかを識別可能で
ある。 The optical signal from the left is transmitted from the transmission line 1-1 to the optical receiver 10-1 via polymer optical waveguides 9-1 and 5-1.
is detected by the connecting cable 12- as an electrical signal.
1 to the node. The signal from the right direction is detected by the optical receiver 10-2 via the waveguides 9-4 and 5-2 from the transmission line 1-2, and is transmitted as an electrical signal to the node via the connection cable 12-4. Therefore, at the node, the connection cable 12-
By monitoring the electrical signals on 1 and 12-2, it is possible to identify whether the signal currently being received is transmitted from a node on the right side of the own node, from a node on the left side, or in both directions. It is.
光信号のような方向性の実現し易い信号を使用
する場合には本方式で必要な方向別送受信機能を
もつ結合装置は第４図の例に示す高分子光回路を
用いて、又はプリズム、ミラーを使用したＴカツ
プラの組合せによつて実現できる。同軸ケーブ
ル、対より線等の伝送路を用いる場合には信号の
方向性を実現するため工夫が必要となる。第５図
は方向性結合装置及びハイブリツド回路を用い
て、同軸ケーブル、対より線のような伝送路用と
しての第２図に示す結合装置を実現した例であ
る。１６−１，１６−２は伝送路、１７−１，１
７−２はハイブリツド回路、１８−１，１８−２
は方向性結合装置、１９−１，１９−２は分岐装
置、２０−１，２０−２は送信信号線、２１−
１，２１−２は受信信号線、２２−１，２２−
２，２３−１，２３−２，２４−１，２４−２は
信号線である。左方からの信号はハイブリツド回
路１７−１により信号線２４−２，２３−２，２
２−２を伝搬し、ハイブリツド回路１７−２を経
由して伝送路１６−２へ伝わるが、信号線２４−
１，２３−１，２２−１へは伝わらない。右方か
らの信号は同様に信号線２２−１，２３−１，２
４−１を伝搬する。方向性結合装置１８−１は右
方からの信号（信号線２３−１経由）と送信信号
（信号線２０−１１経由）を左方へ伝えるが、信
号が方向性結合装置１８−１から信号線２３−１
へ伝わることはない。従つて、分岐装置１９−１
から受信される信号は右方からの信号だけであ
る。左方からの信号についても同じであり、結果
的には第２図と同じ動作を行なう。なお、この場
合、一本の伝送路を双方向に使用するより、結合
装置を第３図のように構成し方向毎に別々の伝送
路を用いる方式がハイブリツド回路が不要となり
実現が容易となる。 When using a signal such as an optical signal whose directionality is easy to realize, the coupling device with the directional transmission/reception function necessary for this method may be a polymer optical circuit shown in the example in Fig. 4, or a prism, This can be achieved by combining a T-coupler using a mirror. When using a transmission path such as a coaxial cable or a twisted pair wire, it is necessary to devise measures to realize the directionality of the signal. FIG. 5 shows an example in which the coupling device shown in FIG. 2 for use in a transmission line such as a coaxial cable or twisted pair wire is realized using a directional coupling device and a hybrid circuit. 16-1, 16-2 are transmission lines, 17-1, 1
7-2 is a hybrid circuit, 18-1, 18-2
is a directional coupling device, 19-1 and 19-2 are branching devices, 20-1 and 20-2 are transmission signal lines, and 21-
1, 21-2 are receiving signal lines, 22-1, 22-
2, 23-1, 23-2, 24-1, and 24-2 are signal lines. The signal from the left is sent to the signal lines 24-2, 23-2, 2 by the hybrid circuit 17-1.
2-2 and is transmitted to the transmission line 16-2 via the hybrid circuit 17-2, but the signal line 24-
It is not transmitted to 1, 23-1, and 22-1. Similarly, signals from the right side are signal lines 22-1, 23-1, 2.
4-1 is propagated. The directional coupling device 18-1 transmits the signal from the right side (via the signal line 23-1) and the transmission signal (via the signal line 20-11) to the left side, but the signal from the directional coupling device 18-1 line 23-1
It will not be transmitted to. Therefore, branching device 19-1
The only signal received from the right side is the signal from the right side. The same goes for the signal from the left, and as a result, the same operation as in FIG. 2 is performed. In this case, rather than using a single transmission line in both directions, it is easier to configure the coupling device as shown in Figure 3 and use separate transmission lines for each direction, which eliminates the need for a hybrid circuit. .
第６図は本発明を用いた衝突ノードの位置識別
装置の具体的な構成例である。２５−１，２５−
２は伝送路、２６は結合装置、２７は送信回路、
２８−１，２８−２はそれぞれ右方向及び左方向
からの信号検出回路、２９は受信回路、３０は衝
突検出回路、３１は位置識別回路である。送信回
路２７から送信中の状態を知らせる信号が衝突検
出回路３０へ送られており、送信中に伝送路から
の信号を信号検出回路、２８−１，２８−２で検
出すると衝突検出回路３０は衝突発生を通知する
信号をノード及び位置識別回路３１へ送る。位置
識別回路３１では衝突発生時に信号を右からのみ
受信したか、左からのみ受信したか、あるいは両
方から受信したかにより、自ノードの位置が衝突
ノード列の左端、右端あるいは他ノードの間にあ
ると判別してノードへ位置を通知する信号を送信
する。 FIG. 6 shows a specific configuration example of a collision node position identification device using the present invention. 25-1, 25-
2 is a transmission path, 26 is a coupling device, 27 is a transmission circuit,
28-1 and 28-2 are signal detection circuits from the right and left directions, 29 is a receiving circuit, 30 is a collision detection circuit, and 31 is a position identification circuit. A signal informing the transmission status is sent from the transmission circuit 27 to the collision detection circuit 30, and when the signal from the transmission path is detected by the signal detection circuits 28-1 and 28-2 during transmission, the collision detection circuit 30 A signal notifying the occurrence of a collision is sent to the node and position identification circuit 31. The position identification circuit 31 determines whether the position of the own node is at the left end, right end, or between other nodes of the colliding node string, depending on whether the signal is received only from the right, only from the left, or from both when a collision occurs. It determines that there is one and sends a signal to notify the node of the location.
以上説明したように、バス上におけるパケツト
の衝突時に各ノードが信号送出中に受信した他ノ
ードからの信号の受信方向を識別することによつ
て衝突ノード列における自ノードの位置を各ノー
ドに分散配置された簡単な回路により判断できる
ことから、識別結果を用いて、衝突時には、衝突
ノードの一端が他端へ順次、送信権を移すことに
より、再衝突が防止できる利点がある。 As explained above, when a packet collides on the bus, each node distributes the position of its own node in the colliding node sequence to each node by identifying the receiving direction of the signal received from other nodes while transmitting the signal. Since the determination can be made using a simple circuit arranged, there is an advantage that re-collision can be prevented by using the identification result to sequentially transfer the transmission right from one end of the colliding node to the other end in the event of a collision.
第１図は本発明の実施例の概略図、第２図は第
１図の結合装置における信号の流れを示す拡大
図、第３図は右方向、左方向独立の伝送路を用い
た場合の結合装置部分の信号の流れを示す拡大
図、第４図は高分子光導波路を用いた第３図の結
合装置の具体的な実現例、第５図は同軸ケーブ
ル、対より線を伝送路として用いた場合の第２図
の結合装置の具体的な実現例、第６図は本発明を
用いた位置識別装置の具体的な構成例である。
１，１−１，１−２……光フアイバ伝送路、２
−１〜２−３……結合装置、３−１〜３−３……
ノード、４−１，４−２……終端装置、５−１，
５−２……信号受信用導波路、６−１，６−２…
…信号送信用導波路、７……分岐集線装置、８−
１，８−２……分岐集線を行なう導波路、９−１
〜９−４……伝送路との接続を行なう導波路、１
０−１，１０−２……光受信装置、１１−１，１
１−２……光送信装置、１２−１〜１２−４……
ノードとの接続用ケーブル、１３……結合装置筐
体、１４−１〜１４−４……結合装置と接続用ケ
ーブルとの接続装置、１５−１〜１５−２……伝
送路と結合装置との接続装置、１６−１，１６−
２……伝送路、１７−１，１７−２……ハイブリ
ツド回路、１８−１，１８−２……方向性結合装
置、１９−１，１９−２……分岐装置、２０−
１，２０−２……送信信号線、２１−１，２１−
２……受信信号線、２２−１，２２−２，２３−
１，２３−２，２４−１，２４−２……信号線、
２５−１，２５−２……伝送路、２６……結合装
置、２７……送信回路、２８−１，２８−２……
右方向及び左方向からの信号検出装置、２９……
受信回路、３０……衝突検出回路、３１……位置
識別回路。
Fig. 1 is a schematic diagram of an embodiment of the present invention, Fig. 2 is an enlarged view showing the signal flow in the coupling device shown in Fig. 1, and Fig. 3 is a diagram showing the case where independent right and left transmission lines are used. An enlarged view showing the signal flow in the coupling device part. Figure 4 is a concrete implementation example of the coupling device in Figure 3 using a polymer optical waveguide. Figure 5 is a coaxial cable and twisted pair wire as a transmission path. FIG. 2 shows a specific implementation example of the coupling device when used, and FIG. 6 shows a specific configuration example of a position identification device using the present invention. 1, 1-1, 1-2...optical fiber transmission line, 2
-1 to 2-3... Coupling device, 3-1 to 3-3...
Node, 4-1, 4-2...Terminal device, 5-1,
5-2... Signal receiving waveguide, 6-1, 6-2...
...Signal transmission waveguide, 7...Branch concentrator, 8-
1, 8-2...Waveguide for branching and concentrating, 9-1
~9-4...Waveguide for connection with transmission line, 1
0-1, 10-2...Optical receiving device, 11-1, 1
1-2... Optical transmitter, 12-1 to 12-4...
Cable for connection with the node, 13... Coupling device housing, 14-1 to 14-4... Connection device between the coupling device and the connection cable, 15-1 to 15-2... Transmission line and coupling device connection device, 16-1, 16-
2... Transmission line, 17-1, 17-2... Hybrid circuit, 18-1, 18-2... Directional coupling device, 19-1, 19-2... Branching device, 20-
1, 20-2... Transmission signal line, 21-1, 21-
2... Reception signal line, 22-1, 22-2, 23-
1, 23-2, 24-1, 24-2...signal line,
25-1, 25-2... Transmission line, 26... Coupling device, 27... Transmission circuit, 28-1, 28-2...
Signal detection device from the right and left directions, 29...
Receiving circuit, 30... Collision detection circuit, 31... Position identification circuit.
Claims (1)
ノードが接続されたコンテンシヨン方式にもとづ
くバス形のローカル・ネツトワーク上で殆ど同時
にバスにパケツト送信を行なうことにより生ずる
該バス上のパケツト衝突時に、該衝突を起こした
ノードがノード列における衝突ノードの位置を識
別する位置識別方式において、 前記バス上の他ノードからの信号を受信し、該
受信した受信信号の方向を検出し、該検出結果に
もとづいて自ノードの位置を識別する手段を有す
る該ノードとバス形の伝送路を接続する結合装置
を備え、パケツト衝突時に衝突を起こした自ノー
ドが受信した他ノードからの該バス上の信号の受
信方向から該他ノードの該自ノードに対する相対
的な位置を識別することにより該自ノードが衝突
を起こしたノード列の両端であるか否か、さらに
どちらの端であるかを検出、識別することを特徴
とするローカル・ネツトワークにおけるパケツト
衝突ノード位置識別方式。[Scope of Claims] 1. On a bus-type local network based on a contention method in which a plurality of nodes including processors or terminal devices are connected, packets are transmitted to the bus almost simultaneously. In a position identification method in which, when a packet collides, the node that caused the collision identifies the position of the colliding node in the node string, the method comprises: receiving a signal from another node on the bus; detecting the direction of the received signal; The node is equipped with a coupling device that connects the node and a bus-type transmission line, which has a means for identifying the position of the own node based on the detection result, and when a packet collides, the own node that has caused the collision receives the bus from another node. By identifying the relative position of the other node to the own node from the receiving direction of the above signal, it is possible to determine whether the own node is at both ends of the node string that caused the collision, and which end it is. A method for identifying the location of packet collision nodes in a local network, which is characterized by detection and identification.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18411381A JPS5885653A (en) | 1981-11-17 | 1981-11-17 | Packet collision node position discriminating system in local network |
| GB08227385A GB2108357B (en) | 1981-09-28 | 1982-09-24 | Method for resolving collision in local network |
| FR8216198A FR2513834B1 (en) | 1981-09-28 | 1982-09-27 | CONFLICT RESOLUTION METHOD IN A LOCAL AREA NETWORK |
| CA000412229A CA1190298A (en) | 1981-09-28 | 1982-09-27 | Method for resolving collision in local network |
| US06/424,532 US4543574A (en) | 1981-09-28 | 1982-09-27 | System for resolving collision in local network |
| DE19823235849 DE3235849A1 (en) | 1981-09-28 | 1982-09-28 | METHOD FOR RESOLVING A COLLISION IN A LOCAL NETWORK |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18411381A JPS5885653A (en) | 1981-11-17 | 1981-11-17 | Packet collision node position discriminating system in local network |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5885653A JPS5885653A (en) | 1983-05-23 |
| JPS6350898B2 true JPS6350898B2 (en) | 1988-10-12 |
Family
ID=16147609
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18411381A Granted JPS5885653A (en) | 1981-09-28 | 1981-11-17 | Packet collision node position discriminating system in local network |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5885653A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5579549A (en) * | 1978-12-13 | 1980-06-16 | Mitsubishi Electric Corp | Bus controller |
-
1981
- 1981-11-17 JP JP18411381A patent/JPS5885653A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5579549A (en) * | 1978-12-13 | 1980-06-16 | Mitsubishi Electric Corp | Bus controller |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5885653A (en) | 1983-05-23 |
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