What is JTAG?
I don't actually know enough about FPGA. I get the whole concept of field programmable gate arrays being able to reconfigure gates to replicate physical hardware architecture...
But beyond that - everyone in the retro community acts like, "What, you don't know about JTAG? Noob!"
And I suspect about 90 % of them know about as much about JTAG as an 80's metalhead who read Tiger Beat but had never actually heard Metallica knew about speed metal.
You can count me in the other 10% who went, "What the eff is a Metallica? Moltey Crue and Def Leppard rock, though!"
Tue Mar 09 2021 18:21:29 EST from Nurb432All the pieces are there to create a risc-ish system now in FPGA out at opencores, and of course other projects. And you can find reasonably priced ( under 500 ) boards that could handle it and be useful. Not saying that an umbrella project to coordinate everything and bring it together would be a bad thing, but if you *want* to do it you can.
Speaking of, i still need to flash that Pano i got with a z80 core + cp/m Just been too lazy to open it up to get to the JTAG port
Basically a hard-coded serial port that bypasses most of the electronics. For diagnostics and programming.
So, otherwise known as a "USB Blaster?"
Wed Mar 10 2021 14:13:03 EST from Nurb432Basically a hard-coded serial port that bypasses most of the electronics. For diagnostics and programming.
Well. that is one version, that converts USB to JTAG.. But not everyone uses USB of course.
At least for Altera, as xilinx calls theirs something a bit more professional sounding :) "Platform Cable"
Fri Mar 12 2021 14:02:16 EST from ParanoidDelusionsSo, otherwise known as a "USB Blaster?"
Wed Mar 10 2021 14:13:03 EST from Nurb432Basically a hard-coded serial port that bypasses most of the electronics. For diagnostics and programming.
Ok. I've got a USB Blaster. It is evidently a good idea with the V4 SA FPGA Amiga - the routine to flash the FPGA through software sometimes fails and bricks the machine, so you have to reflash it with a USB Blaster to fix it.
That helps me understand the terminology better, as a retro-gaming hobbyist. I heart JTAG thrown around quite a bit by developers and the guys who are like... fanatics about knowing all the details so that they can act snobby to the rest of the community - even though they don't *really* know shit about technology. :)
Sat Mar 13 2021 07:24:32 EST from Nurb432Well. that is one version, that converts USB to JTAG.. But not everyone uses USB of course.
At least for Altera, as xilinx calls theirs something a bit more professional sounding :) "Platform Cable"
Fri Mar 12 2021 14:02:16 EST from ParanoidDelusionsSo, otherwise known as a "USB Blaster?"
Wed Mar 10 2021 14:13:03 EST from Nurb432Basically a hard-coded serial port that bypasses most of the electronics. For diagnostics and programming.
Its not *just* for FPGA, but for the discussion here, its what we care about.
And, Altera is on the DE0, so ya, you want the blaster. I have both Altera and Xilinix, so i'm covered either way as far as FPGA is concerned. I honestly dont know what you use if i wanted to stick it on a video card or router or something to do diags or screw with the settings, but I bet its yet another custom converter. Or perhaps just use GPIO and do it manually. Never had to care so never looked.
Its also how to recover phones in the old days when you bricked them screwing around with the firmware when those processes were not as 'proven'. But never bricked a phone so never had to try..
Ok so i was curious and was looking at a few things. Gotta love google and the internet. Before it would have been asking for data books from several companies ( some $ ) and waiting several weeks.. Now, its instant and free.
I wonder now if other than the plug on the board if it really matters which usb/jtag you use. Plug of course is only for convenience. One of mine has several styles, and never really gave it much thought as one 'worked'. I guess if you are using commercial software with it, the software may know which device you have plugging and tell you to go fly a kite, but underneath on the board side, i bet it does not matter.
https://blog.senr.io/blog/jtag-explained
*thumps up*
Sun Mar 14 2021 11:03:18 EDT from Nurb432Its not *just* for FPGA, but for the discussion here, its what we care about.
And, Altera is on the DE0, so ya, you want the blaster. I have both Altera and Xilinix, so i'm covered either way as far as FPGA is concerned. I honestly dont know what you use if i wanted to stick it on a video card or router or something to do diags or screw with the settings, but I bet its yet another custom converter. Or perhaps just use GPIO and do it manually. Never had to care so never looked.
Its also how to recover phones in the old days when you bricked them screwing around with the firmware when those processes were not as 'proven'. But never bricked a phone so never had to try..
If you like Forth, collapseOS seems to have changed over to that and is self hosting on some things now ( 6809 for example )
jtag was the open door china used to exploit all US designed network hardware that was manufactured in china. The red army designed a very tiny jtag bug chip that was in-bedded into the inner-layers of the circuit board. It was nearly impossible to detect the jtag bug chip as they located it in close proximity to other chips that would obscure the bug under xray. China was doing this for over 2 decades. This compromised commercial network traffic and allowed china to significantly spy on US traffic, commercial and some classified military networks. We suspected this was the case for years and significantly cleared Chinese sourced network hardware from secure military nets. Some leakage occurred. A careful forensic analysis identified the bugs and degree of penetration. Time was allowed to pass from discovery to public reveal (2020). The cyberwar is ferocious and unknown to the public. The consequence of the cyberwar has cost many, many lives. This war is far more dangerous than the old cold war espionage of bygone years. The chinese are ethical monsters. Almost all network traffic is completely known by our military, China has been mostly shut out.
Its not the same since Art left the show.
Back during the dark times and i was working nights to keep food on the table ( and a kitchen to have a table in.. ), it was entertaining to listen to his call-in guests. Wack jobs. About the time his show ended, it was time for me to go home. Show before him was Rush, and then the show before that was that business guy that i can never remember his name... he had done *everything* in his life.
Bruce Williams. ( ya, it took me that long to find his name. And I will forget it in about 10 minutes, again )
Agreed. Art Bell was great. As I've mentioned, at one point I was in a circle that included Hoagland and a guy named Mac Tonnies who looked like he was going to be the next big thing in Ancient Alien Astronaut theory.
For some reason, Mac liked to bring me along to private chat sessions with these big guns - and considered me a bona fide "Mars anomaly researcher." I was always too star-struck to really do anything to leverage the opportunity.
https://www.coasttocoastam.com/guest/tonnies-mac-41238/
Sun Apr 11 2021 14:44:33 EDT from Nurb432Its not the same since Art left the show.
Back during the dark times and i was working nights to keep food on the table ( and a kitchen to have a table in.. ), it was entertaining to listen to his call-in guests. Wack jobs. About the time his show ended, it was time for me to go home. Show before him was Rush, and then the show before that was that business guy that i can never remember his name... he had done *everything* in his life.
FORTH exists on most every modern OS out there, and lots of bare metal too. ESP32 is a popular choice of hardware for a FORTH group i help moderate. After loading it you interact via a built-in web-server. We have monthly Zoom meetings too, several hours long. Last meeting Leo Brodie stopped in for a bit to talk.
Tue Apr 13 2021 00:25:18 EDT from ASCII ExpressThanks. I like Forth and wish I could use it more. I've never heard of collapseOS. I use a screen reader and speech synthesizer for the blind, but a minimal computer could drive a synthesizer. Interesting.
This war is far more
dangerous than the old cold war espionage of bygone years. The
chinese are ethical monsters.
"What might save us, me and you, is if the Russians love their children too"
-- Sting
Turns out they did. Not so with China. They don't mind killing a few million of their own if it helps them.
Tell us more about the JTAG bug chip. It's interesting, and now that you mention it, JTAG seems like the obvious place to put an exploit, because it doesn't require messing with the data path in or out of the device.
How did the bug chip connect back to China to deliver the data it captured?
It would seem that sooner or later someone would detect unauthorized traffic on their network using an IDS or something.
I have also heard of it, but from what i remember reading it was pretty targeted. Certain server motherboards and not something widespread.
I think odd traffic was how they found out there was a problem in the first place.
( could be wrong but that is how i remember it when i read about it several years ago )
zaphod indicated the chineese used the jtag bug to make edits to the the firmware after final inspection. the edits were the foundation for later remote exploits that also involved the jtag bug chip. it was a two step process, pretty well thought out. spurious traffic was the loose thread that led to discovery. of course these weren't your typical sites. this is the reason space command exists today. cyber warfare, happens every day. btw, the dominion traffic was captured by the cyber warfare spooks. don't have a clue what, if anything, they intend to do with it.