Ugh. This again. The Ben Eater drawing is wrong - the feedbacks are crossed. [here's Ben Eater's broken version in Falstad][1] [![enter image description here][2]][2] Even with the ‘corrected’ drawing below, know that this is a *latch*, and it doesn’t work correctly. The output definitely does *not* toggle with J and K high. Why? When both inputs are ‘1’ the output oscillates during the time that the clock pulse is high. This is because the two NORs and ANDs form a pair of inverters wired head-to-tail. That, folks, is a *ring oscillator*, a useful circuit by itself, but not here. tl, dr: It’s a junk circuit. Useless, except as a lesson of how *not* to design a latch. [try it here with Falstad. It oscillates][3] [![enter image description here][4]][4] [and finally, a correct JK flip-flop using a pair of latches][5] [![enter image description here][6]][6] [1]: http://www.falstad.com/circuit/circuitjs.html?cct=$%201%200.000005%2010.634267539816555%2050%205%2050%0Aw%20336%20224%20336%20240%200%0Aw%20336%20160%20336%20176%200%0Aw%20432%20224%20432%20256%200%0Aw%20432%20224%20336%20176%200%0Aw%20432%20144%20432%20176%200%0Aw%20432%20176%20336%20224%200%0AM%20432%20144%20496%20144%200%202.5%0AM%20432%20256%20496%20256%200%202.5%0Ax%20422%20117%20440%20120%204%2024%20Q%0Ax%20424%20305%20442%20308%206%2024%20Q%0Aw%2032%20112%2080%20112%200%0Ax%2030%2047%2042%2050%204%2024%20J%0AR%2064%20336%2032%20336%201%202%20120%202.5%202.5%200%200.5%0Aw%20336%2064%2080%2064%200%0Aw%2080%2064%2080%20128%200%0AL%2032%20256%2032%20224%200%200%20false%205%200%0Ax%2024%20193%2040%20196%204%2024%20K%0Aw%2064%20336%2064%20256%200%0Aw%2064%20256%2080%20256%200%0Aw%2080%20144%2064%20144%200%0Aw%2064%20144%2064%20256%200%0Aw%2032%20288%2032%20256%200%0Aw%2032%20288%2080%20288%200%0Aw%20336%20368%2080%20368%200%0Aw%2080%20368%2080%20272%200%0AL%2032%20112%2032%2080%200%200%20false%205%200%0A150%2080%20128%20160%20128%200%203%200%205%0A150%2080%20272%20160%20272%200%203%200%205%0Aw%20336%20240%20336%20368%200%0Aw%20336%2064%20336%20160%200%0A153%20352%20144%20432%20144%200%202%200%205%0A153%20352%20256%20432%20256%200%202%205%205%0Aw%20336%20240%20352%20240%200%0Aw%20336%20160%20352%20160%200%0Aw%20352%20128%20160%20128%200%0Aw%20160%20272%20352%20272%200%0Ao%2025%2064%200%204102%200.0000762939453125%200.00009765625%200%202%2025%203%20J%0Ao%2015%2064%200%204102%200.0000762939453125%200.00009765625%200%202%2015%203%20K%0Ao%206%2064%200%204102%200.0000762939453125%200.00009765625%200%201%20Q%0Ao%2012%2064%200%204102%205%200.00009765625%200%202%2012%203%20clk%0A [2]: https://i.sstatic.net/G9GrKm.png [3]: http://www.falstad.com/circuit/circuitjs.html?cct=$%201%200.000005%2010.634267539816555%2050%205%2050%0Aw%20336%20224%20336%20240%200%0Aw%20336%20160%20336%20176%200%0Aw%20432%20224%20432%20256%200%0Aw%20432%20224%20336%20176%200%0Aw%20432%20144%20432%20176%200%0Aw%20432%20176%20336%20224%200%0AM%20432%20144%20496%20144%200%202.5%0AM%20432%20256%20496%20256%200%202.5%0Ax%20422%20117%20440%20120%204%2024%20Q%0Ax%20424%20305%20442%20308%206%2024%20Q%0Aw%2032%20112%2080%20112%200%0Ax%2030%2047%2042%2050%204%2024%20J%0AR%2064%20336%2032%20336%201%202%20120%202.5%202.5%200%200.5%0Aw%20336%2064%2080%2064%200%0Aw%2080%2064%2080%20128%200%0AL%2032%20256%2032%20224%200%201%20false%205%200%0Ax%2024%20193%2040%20196%204%2024%20K%0Aw%2064%20336%2064%20256%200%0Aw%2064%20256%2080%20256%200%0Aw%2080%20144%2064%20144%200%0Aw%2064%20144%2064%20256%200%0Aw%2032%20288%2032%20256%200%0Aw%2032%20288%2080%20288%200%0Aw%20336%20368%2080%20368%200%0Aw%2080%20368%2080%20272%200%0AL%2032%20112%2032%2080%200%201%20false%205%200%0A150%2080%20128%20160%20128%200%203%200%205%0A150%2080%20272%20160%20272%200%203%200%205%0Aw%20432%20256%20432%20368%200%0Aw%20432%20368%20336%20368%200%0Aw%20336%2064%20432%2064%200%0Aw%20432%2064%20432%20144%200%0A153%20352%20144%20432%20144%200%202%205%205%0A153%20352%20256%20432%20256%200%202%200%205%0Aw%20336%20240%20352%20240%200%0Aw%20336%20160%20352%20160%200%0Aw%20352%20128%20160%20128%200%0Aw%20160%20272%20352%20272%200%0Ao%2025%2064%200%204102%205%200.00009765625%200%202%2025%203%20J%0Ao%2015%2064%200%204102%205%200.00009765625%200%202%2015%203%20K%0Ao%206%2064%200%204102%205%200.00009765625%200%201%20Q%0Ao%2012%2064%200%204102%205%200.00009765625%200%202%2012%203%20clk%0A [4]: https://i.sstatic.net/HwZ27m.png [5]: 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[6]: https://i.sstatic.net/h5R0Wm.png