The filming of Scrubs takes place in Los Angeles, California in the North Hollywood Medical Center (a non-operational hospital). The fictional place that Sacred Heart is located in Scrubs is known as San DiFrangeles. Which happens to be a mixture of the name San Diego, San Francisco, and Los Angeles.
JTAG is an IEEE standard (1149.1) developed in the 1980s to solve electronic boards manufacturing issues. Nowadays it finds more use as programming, debug and probing port. But first, let's see JTAG's original use, boundary testing. Boundary testing
The JTAG pins are usually dedicated (not shared for other purposes). All big ICs use boundary testing using JTAG - boundary testing is the original reason JTAG was created. But wouldn't it be nice to use JTAG for more purposes than just boundary testing? CPU and FPGA manufacturers allow JTAG to be used as debug port.