Reverse 3X playback on the Sony LDP-1450 explained in detail

Since Time Traveler plays backward at 3X, I decided to gather some details about how this works on the Sony LDP-1450.  I have collected data on both what fields are displayed and also when the reverse playback takes place.

Here are some screenshots showing the transition from 1X forward to 3X backward, along with decoded VBI picture numbers.  The blue window on the right represents the serial port commands sent to the player and the responses received from the player (updated as close to real-time as possible).  I used a camcorder to record them side by side.

Here is a list of the VBI picture numbers before, during, and after the transition from 1X forward to 3X reverse.  The text in green is what is represented by the screen shots.

Track 659 Field 1 WhiteFlag:0 L16:000000 L17:fb0659 L18:fb0659 (30659)
Track 660 Field 0 WhiteFlag:0 L16:000000 L17:ab0659 L18:ab0659
Track 660 Field 1 WhiteFlag:0 L16:000000 L17:fb0660 L18:fb0660 (30660)
Track 661 Field 0 WhiteFlag:0 L16:000000 L17:ab0660 L18:ab0660
Track 661 Field 1 WhiteFlag:0 L16:000000 L17:fb0661 L18:fb0661 (30661)
Track 662 Field 0 WhiteFlag:0 L16:000000 L17:ab0661 L18:ab0661
Track 662 Field 1 WhiteFlag:0 L16:000000 L17:fb0662 L18:fb0662 (30662)
Track 663 Field 0 WhiteFlag:0 L16:000000 L17:ab0662 L18:ab0662
Track 663 Field 1 WhiteFlag:0 L16:000000 L17:fb0663 L18:fb0663 (30663)
Track 664 Field 0 WhiteFlag:0 L16:000000 L17:ab0663 L18:ab0663
Track 664 Field 1 WhiteFlag:0 L16:000000 L17:fb0664 L18:fb0664 (30664)
Track 665 Field 0 WhiteFlag:0 L16:000000 L17:ab0664 L18:ab0664
Track 665 Field 1 WhiteFlag:0 L16:000000 L17:fb0665 L18:fb0665 (30665)
Track 666 Field 0 WhiteFlag:0 L16:000000 L17:ab0665 L18:ab0665
Track 666 Field 1 WhiteFlag:0 L16:000000 L17:fb0666 L18:fb0666 (30666)
Track 667 Field 0 WhiteFlag:0 L16:000000 L17:ab0666 L18:ab0666
Track 667 Field 1 WhiteFlag:0 L16:000000 L17:fb0667 L18:fb0667 (30667)
Track 668 Field 0 WhiteFlag:0 L16:000000 L17:ab0667 L18:ab0667
Track 668 Field 1 WhiteFlag:0 L16:000000 L17:fb0668 L18:fb0668 (30668)
Track 669 Field 0 WhiteFlag:0 L16:000000 L17:ab0668 L18:ab0668
Track 669 Field 1 WhiteFlag:0 L16:000000 L17:fb0668 L18:fb0668 (30668)
Track 670 Field 0 WhiteFlag:0 L16:000000 L17:ab0666 L18:ab0666
Track 670 Field 1 WhiteFlag:0 L16:000000 L17:fb0665 L18:fb0665 (30665)
Track 671 Field 0 WhiteFlag:0 L16:000000 L17:ab0663 L18:ab0663
Track 671 Field 1 WhiteFlag:0 L16:000000 L17:fb0662 L18:fb0662 (30662)
Track 672 Field 0 WhiteFlag:0 L16:000000 L17:ab0660 L18:ab0660
Track 672 Field 1 WhiteFlag:0 L16:000000 L17:fb0659 L18:fb0659 (30659)
Track 673 Field 0 WhiteFlag:0 L16:000000 L17:ab0657 L18:ab0657
Track 673 Field 1 WhiteFlag:0 L16:000000 L17:fb0656 L18:fb0656 (30656)
Track 674 Field 0 WhiteFlag:0 L16:000000 L17:ab0654 L18:ab0654
Track 674 Field 1 WhiteFlag:0 L16:000000 L17:fb0653 L18:fb0653 (30653)
Track 675 Field 0 WhiteFlag:0 L16:000000 L17:ab0651 L18:ab0651
Track 675 Field 1 WhiteFlag:0 L16:000000 L17:fb0650 L18:fb0650 (30650)
Track 676 Field 0 WhiteFlag:0 L16:000000 L17:ab0648 L18:ab0648
Track 676 Field 1 WhiteFlag:0 L16:000000 L17:fb0647 L18:fb0647 (30647)
Track 677 Field 0 WhiteFlag:0 L16:000000 L17:ab0645 L18:ab0645
Track 677 Field 1 WhiteFlag:0 L16:000000 L17:fb0644 L18:fb0644 (30644)
Track 678 Field 0 WhiteFlag:0 L16:000000 L17:ab0642 L18:ab0642
Track 678 Field 1 WhiteFlag:0 L16:000000 L17:fb0641 L18:fb0641 (30641)
Track 679 Field 0 WhiteFlag:0 L16:000000 L17:ab0639 L18:ab0639
Track 679 Field 1 WhiteFlag:0 L16:000000 L17:fb0638 L18:fb0638 (30638)
Track 680 Field 0 WhiteFlag:0 L16:000000 L17:ab0636 L18:ab0636
Track 680 Field 1 WhiteFlag:0 L16:000000 L17:fb0635 L18:fb0635 (30635)
Track 681 Field 0 WhiteFlag:0 L16:000000 L17:ab0633 L18:ab0633
Track 681 Field 1 WhiteFlag:0 L16:000000 L17:fb0632 L18:fb0632 (30632)
Track 682 Field 0 WhiteFlag:0 L16:000000 L17:ab0630 L18:ab0630
Track 682 Field 1 WhiteFlag:0 L16:000000 L17:fb0629 L18:fb0629 (30629)
Track 683 Field 0 WhiteFlag:0 L16:000000 L17:ab0627 L18:ab0627
Track 683 Field 1 WhiteFlag:0 L16:000000 L17:fb0626 L18:fb0626 (30626)
Track 684 Field 0 WhiteFlag:0 L16:000000 L17:ab0624 L18:ab0624
Track 684 Field 1 WhiteFlag:0 L16:000000 L17:fb0623 L18:fb0623 (30623)

Conclusion:

Playing backward seems to happen almost instantly.  For Dexter purposes, I should be able to make it happen instantly without any problem.

Also, when playing 3X reverse, complete tracks are not displayed, but instead the laserdisc player is skipping backward 3 fields every field.  This means that the picture will most likely always be interlaced with two unrelated frames when playing in this mode.