These diodes are the only "specialty" item that is needed to perform the old school JTAG modification. The only additional things you would need are some bits of wire, and a way to read/write the nand (JRP or Nandx).
Remember - JTAG can ONLY be done to consoles on dashboard 2.0.7371 and below - they are VERY rare in 2018!
**Note: Purchase of supplies from my shop does not entitle you to me personally supporting your install. I'll try to help out with questions or issues as much as I can, but my personal support of your install is not guaranteed. If you need help, check out weekendmodder.com/helpme for some guidance on the type of info I need and then use the "contact" page to reach out to me.
***I'm only listing these here due to many, many request - my advice would be that you simply buy a whole bunch of these diodes off of eBay for super cheap.
This diagram references using an LPT cable to read/write the nand, and I would suggest you consider a JRP or a Nandx instead, but it does still correctly show how to install the 1N4148 diodes for the JTAG wiring (the yellow, red, and blue lines) This image would apply to NON-xenon consoles