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→JTAG/Programming/CPLD
JTAG pads are exposed on the PCB as seen in the image above. I could connect to these to read the CPLD. Pretty soon they were pulled off the board, and I had to solder a pin to the leg temporarily to continue reading data. (before I discovered tiny IC clips!)
[Only one device is visible in the JTAG chain, the Xilinx. The CPU, [https://www.alldatasheet.com/datasheet-pdf/download/249501/RENESAS/H8SLASH300H.html H8300H] (Hitachi/Renesas) is not equipped with JTAG at all. Low level CPU operation is done through a bootloader mode] Interesting and lovely late 1990s marketing publication [https://www.ele.uva.es/~jesman/BigSeti/ftp/Microcontroladores/Hitachi/H8-300H/h8_16bit.pdf here]
I connected to the [https://www.datasheet.live/pdfviewer?url=https%3A%2F%2Fwww.datasheet.live%2Fdatasheet%2Fxilinxsemi%2FXC95144XL-7TQ100C0962.pdf Xilinx XC95144] using [https://github.com/Aodrulez/blueTag/tree/main Bluetag], [https://openocd.org/ OpenOCD] and [https://github.com/MPLew-is/xc3sprog XC3SPROG] (open source Xilinx CLI) and was eventually able to read back ID codes and find IR Len etc. I was happy it was responding. It was fun, confusing and difficult to set up all these tools. I set most of them up on a Raspberry Pi as dedicated hacking server so I can connect remotely to the hot mess setup with my laptop, somewhere more comfortable : )