The vdp object works with serially-controlled videodisk players (remember them?) that are compatible with the Pioneer 4200 or 8000 standard. Each command received by the vdp object sends a stream of numbers out the object's left outlet, intended to be connected to the serial object. The description of each command discusses what effect the command has on the player, not the exact character stream sent by vdp.
Because videodisc players have relatively buffer-less serial interfaces, vdp places each command it receives in a queue, and sends it out only when the player has finished executing its most recent command. This "feature" may cause a delay between the time a command is sent to the vdp object and the time it is actually sent out the serial port.
Any message received in the right inlet will behave exactly as if it had been received in the left inlet, except that it will be put at the front of the queue, to be the very next command sent out to the player.
Common Box Attributes
In middle inlet: vdp expects responses from the player to be fed from the serial object into its middle inlet. When vdp sees "received" (the letter followed by the return character) from the player, it sends the next command from its queue of pending commands. The example shows how to connect the vdp and serial objects together.
0 --------- Initialize and reset player
1 --------- Eject disk
2 --------- Audio off
3 --------- Audio 1 on
4 --------- Audio 2 on
5 --------- Stereo on
6 --------- Picture on
7 --------- Picture off
8 --------- Display frame numbers on
9 --------- Display frame numbers off
11 ------- Frame access mode
12 ------- Time access mode
13 ------- Chapter access mode
display-flag (0 or non-zero) [int]
Out middle-left outlet: After sending a command out its left outlet, vdp begins "polling" the serial object for a response from the player by sending messages out this outlet approximately every 20 milliseconds, until vdp receives a "received" signal from the player in its right inlet. (A sent to a serial object causes any characters received in that serial port to be sent out the serial object's outlet.)
Out left outlet: A stream of characters, coded instructions to the videodisc player, for each command. These numbers are intended to be sent to the left inlet of a serial object.
Out middle-right outlet: Current frame number, received from the player in response to amessage.
Out right outlet: Not implemented.
|Using Max with Hardware||Using Max with Hardware|