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Description of the DPY (display) board
The display board is composed of one C.I. 8 bit shift register (74C164), an 8 darlington driver, 7 current limiting resistors and 6 digits of 10.000 points, etc. forming columns. Each one of these columns is supplied from the IOS board, independent from the others and sequencially, so that only one of the 6 digits of each board is lit in a given moment. As this process is effected at an speed of 50 times per second, the observer eyes creates the optical illusion that all digits are lit simultaneously.
Previous to the connexion of the anodes of each column, the cathodes of the segments of each digit to be lit are chosen, in order to form the wished number.
A shift-register as the ones used, when receiving a pulse from its CK input, situates at the A output the information which was at the DATA input. Simultaneously, the information which was at A passes to B, the one in B to C, and son on.
From the IOS board the 5 CK inputs of the 5 display boards and the DATA input of the display of the first PLAYER are driven. The output H of this display is connected to the DATA input of the display of the second PLAYER and so on until the display of the STATUS.
From the IOS board, before connecting a certain column, 40 pulses are sent for the connection CKD that supplies the inputs CK of the displays. Before every pulse DATA will be high or low, whether the segment to which such information must arrive will lit or not. Evidently, the eight first pulses correspond to the STATUS display, from nine to sixteen to the display of the fourth PLAYER, from seventeen to twenty four to the display of the third PLAYER, from twenty five to thirty two to the display of the second PLAYER and from the thirty three to the forty to the display of the first PLAYER.
Once the segments have been selected, such informations, amplified by the drivers and limited their current by the resistors, are carried to the cathodes of the LED. The cathodes of the segments that occupy the same position in the six digits of every display are connected all together. Obviously, it will only lit the digits of the column which is supplied at this moment from the IOS board.
After 3 miliseconds, the dolumn is disconnected, the information of the following segments updated and the column supplied, and so on.
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		www.FLIPPERS.be your guide to pinball in Belgium

Description of the DPY (display) board The display board is composed of one C.I. 8 bit shift register (74C164), an 8 darlington driver, 7 current limiting resistors and 6 digits of 10.000 points, etc. forming columns. Each one of these columns is supplied from the IOS board, independent from the others and sequencially, so that only one of the 6 digits of each board is lit in a given moment. As this process is effected at an speed of 50 times per second, the observer eyes creates the optical illusion that all digits are lit simultaneously. Previous to the connexion of the anodes of each column, the cathodes of the segments of each digit to be lit are chosen, in order to form the wished number. A shift-register as the ones used, when receiving a pulse from its CK input, situates at the A output the information which was at the DATA input. Simultaneously, the information which was at A passes to B, the one in B to C, and son on. From the IOS board the 5 CK inputs of the 5 display boards and the DATA input of the display of the first PLAYER are driven. The output H of this display is connected to the DATA input of the display of the second PLAYER and so on until the display of the STATUS. From the IOS board, before connecting a certain column, 40 pulses are sent for the connection CKD that supplies the inputs CK of the displays. Before every pulse DATA will be high or low, whether the segment to which such information must arrive will lit or not. Evidently, the eight first pulses correspond to the STATUS display, from nine to sixteen to the display of the fourth PLAYER, from seventeen to twenty four to the display of the third PLAYER, from twenty five to thirty two to the display of the second PLAYER and from the thirty three to the forty to the display of the first PLAYER. Once the segments have been selected, such informations, amplified by the drivers and limited their current by the resistors, are carried to the cathodes of the LED. The cathodes of the segments that occupy the same position in the six digits of every display are connected all together. Obviously, it will only lit the digits of the column which is supplied at this moment from the IOS board. After 3 miliseconds, the dolumn is disconnected, the information of the following segments updated and the column supplied, and so on. Playmatic repair main page Main
© Flippers.be