The JTAG connector seems to be the same as the h1910's, without the SRST line connected (certainly no detectable results with using it). JTAG is brought to card edge pads on the RX1950, only front side pins are needed and GND. The front side of the board has the CPU and the DRAM and pins 1,3,5,7 of the JTAG connector: /--------------|_|-----------------------------------------| | [7][5][3][1] | | | | | |-- TCK | | |----- TMS | |-------- TDI |----------- TDO The back side of the board has pins 2,4,6,8, where 2 is behind 1, 4 is behind 3, 6 is behind 5, and 8 is behind 7. Here is a view through the board: /--------------|_|-----------------------------------------| | [8][6][4][2] | | | | | |-- TRST# | | |----- SRST# | |-------- GND |----------- GND The ground pins are easy to identify because they are part of a ground plane or pour.