[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)
 
web link (tomverbeure.github.io)
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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(page generated 2023-12-28 23:00 UTC)