[HN Gopher] Remote controlling an HP 1670G logic analyzer with a...
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Remote controlling an HP 1670G logic analyzer with a Linux PC X
server
Author : zdw
Score : 50 points
Date : 2023-12-27 03:32 UTC (1 days ago)
(HTM) web link (tomverbeure.github.io)
(TXT) w3m dump (tomverbeure.github.io)
| branon wrote:
| Now do it with Xwayland, any differences?
| tverbeure wrote:
| I don't know anything about Xwayland, but there's this sentence
| in this socat writeup:
|
| > If you want to access an X server that does not provide
| -listen tcp (Xwayland) or just did not have enabled it during
| startup (like most likely your host Xorg), you can use socat to
| provide TCP/IP access.
|
| https://github.com/mviereck/x11docker/wiki/How-to-access-X-o...
|
| This makes me think that socat is exactly what you need to make
| it work with Xwayland?
| hsbauauvhabzb wrote:
| In my experience, a dedicated virtual machine running
| $problematic_stack often beats any workarounds - there's
| often not enough people power to make niche workarounds like
| that work well, sometimes they're brilliant, other times
| they're barely functional.
| yjftsjthsd-h wrote:
| It's probably exactly the same?
| amstan wrote:
| My friend wrote a blog post about a similar model:
| http://www.theresistornetwork.com/2013/12/a-testament-to-x11...
| tverbeure wrote:
| That's interesting!
|
| I spent hours getting things to work the way they described it:
| xhost, xauth, Xorg, xserverrc, gdm3/custom.conf, and nothing
| stuck. I probably did something wrong. I'll add this blog post
| as a reference to mine.
|
| I really like the socat option though. Other than opening a
| single TCP/IP port, it doesn't require changes to config files
| anywhere. I've just updated the blog post to make the UFW
| config more strict, by only allow TCP requests from the logic
| analyzer IP address.
|
| BTW, your friend's search engine optimization game is a bit
| lacking. The title is not very descriptive. ;-)
| aarossig wrote:
| It was actually on HN a while back:
| https://news.ycombinator.com/item?id=6850591
|
| Glad you found the old blog of mine insightful.
| neilv wrote:
| The writeup didn't mention it, but I'd guess probably that logic
| analyzer supports X authorization, which means that there's an
| alternative with different security properties:
|
| 1. Make sure that X's `xauth` for is set up on your
| laptop/workstation.
|
| 2. Enable TCP listening of the X server (like the server used to
| do by default, back when people were doing remote X display like
| this). This is in lieu of running `socat`, so, when you configure
| the logic analyzer TCP/IP, you'd tell it the X server's normal
| TCP port instead of the `socat` one.
|
| 3. Set the `xauth` secret on the logic analyzer.
|
| (Also, if the `ifconfig` in the blog post doesn't work for you,
| try `ip a`.)
|
| A downside of this is that authorization secret would be accepted
| by the server an indefinite period of time after you're done
| using the logic analyzer.
|
| A more secure alternative is to forget about X, and instead plug
| a compact PS/2 keyboard and pointing device into the logic
| analyzer. (IBM sold some compact keyboards with integrated
| TrackPoint and touchpad pointing devices, which take no more
| bench space than a laptop does.) I'd guess screenshots are a
| headache, though.
| tverbeure wrote:
| > I'd guess probably that logic analyzer supports X
| authorization, ...
|
| Unfortunately, it doesn't. The screenshots in the blog posts
| are pretty much all there is. But even if it did, I wasn't even
| able to make my Linux laptop display an xclock on my desktop
| screen until I used the socat option. There's too many config
| files to get right. socat doesn't require any of that and it's
| only active when using the logic analyzer.
|
| > A more secure alternative is to forget about X, and instead
| plug a compact PS/2 keyboard and pointing device into the logic
| analyzer.
|
| Not enough room. Bulky test equipment like this lives on an
| equipment cart (I love it!) but it makes using a keyboard and
| mouse awkward. I'm not too worries about the security issues,
| TBH. In the unlikely case that attackers go through the trouble
| of entering my home network (why?), they're better at network
| ops than I am. The Linux machine that drives all this is for
| development only. All the stuff on there can be downloaded from
| my GitHub repos...
| neilv wrote:
| My bad. Looks from the manual like they assume `xhost +` for
| the analyzer's IP address. I like your approach best.
| ComputerGuru wrote:
| > IBM sold some compact keyboards with integrated TrackPoint
| and touchpad pointing devices, which take no more bench space
| than a laptop does.
|
| It's not the greatest keyboard for typing, but the Logitech
| K400 is a decent modern alternative for such purposes. You'd
| need a USB-to-PS/2 adapter, though:
|
| https://www.amazon.com/Logitech-Wireless-Keyboard-Touchpad-P...
| neilv wrote:
| A bit more compact, the IBM SK-8845 can still be gotten on
| eBay with native PS/2 interfaces (or USB, in some variants):
| http://www.ibmfiles.com/pages/sk88xx.htm
|
| The SK-88*4*5 are actually a little easier/cheaper to get
| than the later SK-88*5*5, maybe because the earlier model
| doesn't have Win95 keys.
|
| (The SK-8855 was also noteworthy for Lenovo soliciting user
| input in its design, before they seemed to go all-in on a
| consumer Mac-like aesthetic. Now, SK-8855 and earlier
| TrackPoint keyboards sell used for more than they cost new,
| even if dirty, since Lenovo isn't making them like that
| anymore. Even though were only ever lightweight laptop-like
| keyboards, not veritable battleships like some historical
| earlier IBM mechanical keyboards.)
| cricalix wrote:
| This looks remarkably similar to the one Tech Tangents
| (twitch/youtube) has hooked up to GPIB with Python tooling for
| automating cap reforming. Pretty sure he has VGA type capture
| working too, so he can hook it in to OBS for his streams (and
| overlays the Python automation via a web page).
| AkBKukU wrote:
| Mine (I run Tech Tangents) is a 16500C and the interface is
| basically identical. The problem with remote access for these
| is that they draw traces to the screen using direct framebuffer
| access rather than X11 calls meaning you can't see them
| remotely. So the best you can do send them commands remotely
| and read the numerical results. That's why I went the VGA
| capture route.
| Aloha wrote:
| Huh.
|
| I wonder what other HP/Agilent gear supported this - I have a
| service monitor that I'm pretty sure does not - but a scope would
| be nice.
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