JTAG Port - FAQ
This FAQ will show you how to retrieve the boxkey from your x700, x800 and x900 model Receiver’s, using the JTAG port. Older models, such as 3000, 3500, 4000, 4500, and Dishplayers 7100 & 7200 do NOT work as there is no JTAG port, only a high speed serial port on the back which will not work.

What is JTAG, What does it look like? Often called Boundary scan. The JTAG- Joint Test Action Group, named after the group that developed it. It is the IEEE 1149.1 boundary scan standard. This standard governs use and testing of Flash/PLD programming, like the ST55** microchip. Simply said we can use this connector/port to retrieve the boxkey of Dishnet Ird's.
Look at the following diagram. This is the JTAG connector. If the long Gnd is on top. The Big 7 Solder Pads is right below it. Below this is a 20 pin connector
Look at the bottom of your IRD, there should be a rectangular hole. Look inside and you should see.
The 20 pin connector counts like

19 17 15 13 11 9 7 5 3 1
20 18 16 14 12 10 8 6 4 2

Notice you count across and not down each row for the 20 pin connector. The pins we are concerned with are as follows.
Look at the bottom of your IRD, there should be a rectangular hole. Look inside and you should see....
One long GND Pad ====================
Big 7 Solder Pads [] [] [] [] [] [] []
20 Pin Connector : : : : : : : : : :
Big 7 JTAG - Description

Solder Pad

1 ----- Unknown - ?

2 ------ 9 - TMS (Input from PC)

3 ----- 11 - TCK (Input from PC)

4 ----- 13 - TDI (Data Input from PC)

5 ----- 15 - TDO (Data Output to PC)

6 ----- 19 - /TRST (Input Active Low)

7 ------17 - /Reset
Fortunately for us, the Big 7 Solder Pads has all the pins we need to read the boxkey. These pads duplicate the connectors we need on the 20 pin connector. We can use these solder Pads which can be reached w/o opening the IRD, which is easier to solder versus the 20 pin connector. The only pins we are concerned with on the Big 7 Solder Pads are pins 2-6... we don't use pin 1 & 7. We will also solder to GND on the long GND pad.

This is how we hook up these points to the parallel port of our computer.

LPT DB-25(pin) ----- Big 7 Solder Pads
2 ---------------------------------- 2
3 ---------------------------------- 3
4 ---------------------------------- 4
5 ---------------------------------- 6
13 -------------------------------- 5
18 -------------------------------- 25 Long GND

Since our DB-25, LPT port generates 5 volts, we want to limit the current across several pins. Here is a basic schematic.
D1-D4 = any LED, D5 = any silicon diode (i.e., 1N4004-4007) R1, R2, R3, R5 resistors = 100 Ohms., R4 = 33 Ohms

There's no need to power this schematic...

Any LED should work. Most have a direct falling voltage >2.5 volt. Any diode should work as well.
This Circuit, SimpleJTAG.brd is simple to build. I used Eagle s/w to print board. You can get a demo copy of this software at www.CadSoftUSA.COM. This board is very small, so you can make many PCB boards. The output of the board has the 6 pins oriented in order so that you can solder to the IRD easier.
The circuit can be built on a perforation board as well, for you non-PCB’ers... Here is one that I built with only a few spare parts.
I used this simple board because I had trouble using the other schematic with the 74HC244 chip. I'm not sure what went wrong but I get the wrong IDcode using that design when I run the JTAG s/w.

Some have warned against using this setup because the 5 volts from the LPT port on the computer may damage the IRD... but I have had no problems. The led’s and diode should be safe. I have retrieved boxkeys from several IRD’s so far, including, the 2700, 2800, 3700, 3800 and 4700 models... all x700, x800, x900 models and the new 301's have the JTAG port. I've heard a rumor that the new 501's have a JTAG port as well but I don't have one to verify.

Older models, such as 3000, 3500 and 4500, do NOT work as there is no JTAG port, they have only a high speed serial port on the back which will not work.
Connecting the JTAG to the IRD.
Usual safety rules - turn off IRD, Solder Leads to the Big 7 Solder Pads, turn on IRD. When disconnecting leads, always cut-off IRD and pull plug. NEVER CONNECT A CABLE WHILE IRD IS ON!
Running the JTAG_P program…

Open a MS-Dos prompt. This can be done from windows. Go to folder with the JTAG_P.exe… type JTAG_P to run the program.

You should get an IDCODE=2D4C9041 - if you don't get this code, you probably won't get the correct info. Some people have reported different results on different computers. Faster computers seem to do better. If you get an error of “test wiggler” or something like that then recheck all your connections. Make sure you didn’t get any stray solder on surrounding pins. Make sure your IRD is unplugged while jiggling your contacts, etc… else you could cause a short.

JTAG_P.exe will then say, “I don’t know this IDCODE
Continue ? [y/n] :
Start Address [hex] : 7FFFFFC0 <- Use this as the starting value

Data Len [hex] : C <- Use this as the 12 bytes needed for Ird/boxkey

StartAddr=7FFFFFC0 DataLen=C
All o’k ? [y/n] : y <- Make sure you use lower caps

See read data in out.bin <-Your IRD and Boxkey is contained here.
Use Hexed.exe to read your Out.bin. Type Hexed out.bin in MS-Dos window to read your bin. The first 4 bytes is your IRD (hex)… The last 8 bytes is your Boxkey.
Congratulations… Using your boxkey, you can now program a card to use in it.

Note:
If you don't get right IDCODE=2D4C9041, your setup has something wrong.
Verify that your BIOS setting is set to 'standard' parallel port.

Once again, older models like 3000, 3500, 4000, 4500 and 4500 are not designed around the STi5500, so they don't have a JTAG port anyway. So rule those out... Same story for Model 1000.
IRD awaiting boxkey retrevial. Once I get boxkey, I won't need AVR3 (seen here). Too bad Dishplayer doesn't have a JTAG, but this one had boxkey on its subbed card anyway.
Attempt to build JTAG with the 74HC244 chip. It didn't work for me!
Few other IRD's awaiting JTAG read
Happy Testing
Mac4Lyfe

Thanks goes out to Nightowl for excellent Picture of JTAG port.

Thanks to Lithster for keeping the scene clean.

And all the excellent Ops at #DISHNET on IRC