HD74LS112 Dual J-K Negative-edge-triggered Flip-Flops (with Preset and Clear)

HD74LS112 Dual J-K Negative-edge-triggered Flip-Flops (with Preset and Clear)
https://www.youtube.com/watch?v=jmsqK1GV77E
  1. HD74LS112P
  2. NE555P