Troubleshooting MMI 3G

Reply Subscribe

Thread Tools

Search this Thread

12-26-2023, 12:46 PM

#31

sm87

AudiWorld Junior Member

Thread Starter

Join Date: Jan 2014

Posts: 33

Likes: 1

Received 2 Likes on 2 Posts

@drgertol cat should work all the same for this. However I don't think you can simply read that device to dump the data, there's a whole pile of "components" multiplexed behind that named pipe, the MMI EEPROM being just one of them. First a request needs to get written to that file, perhaps there's some session-initialization required too.
Found documentation for the protocol https://github.com/DSIHarman/DSI/blo...cification.pdf but there's nothing audi-specific in there, . (Still have no idea what "DSI" means, AppleTalk had a layer called "DSI" but doesn't seem to be related at all.)

@AudiAllTheWay If I can't get the original MMI module to boot I may need to desolder that chip just to read it with a programmer, but that's a bit easier than putting it back

One thing I still haven't checked is if the old HDD is OK, probably been a decade since I've seen a PATA connector in person. It was cheaper to get the whole replacement MMI unit than a ATA drive, maybe I'll try transplanting the HDD to try and revive the old MMI...

Reply Like

12-26-2023, 01:59 PM

#32

drgertol

AudiWorld Member

Join Date: Aug 2011

Location: NW OH

Posts: 494

Likes: 28

Received 84 Likes on 78 Posts

@sm87 -- "cat /dev/dsi/data > file.dat" returns a zero-byte file and message "/dev/dsi/data: Resource busy" (which I half expected). Later H-B MIB systems appear to have a command-line tool/binary (pc) for this purpose: https://rennlist.com/forums/991/1049...l#post16053504
Knowledge of the related Engineering Screen Definition data field specs (e.g., name space & key/address) is useful here (found in directory /mnt/efs-system/engdefs).

Re the HDD in MMI3G systems, it is not needed for the QNX system to start & run -- the HDD in the original main unit is likely OK. You need a QNX VM to inspect the drive partitions -- I describe the process here: https://www.vwvortex.com/threads/mmi...post-115975309 --g

Reply Like

12-30-2023, 01:26 PM

#33

sm87

AudiWorld Junior Member

Thread Starter

Join Date: Jan 2014

Posts: 33

Likes: 1

Received 2 Likes on 2 Posts

Quote:

Originally Posted by drgertol

Later H-B MIB systems appear to have a command-line tool/binary (pc) for this purpose: https://rennlist.com/forums/991/1049...l#post16053504

I was thinking it would be quite straight forward to create a utility like that in Java using the decompiled sources. The J9 JVM is open source since 2017 but I don't think one needs to touch it at all, from what I can tell the J9 on the MMI corresponds to J2SE 1.5 (aka J2SE 5.0) which you can easily target with modern JDK versions. Also if you look at the end of /efs-system/lsd/lsd.sh script in addition to .jxe it can run from .jar, and .class files like any standard Java runtime, so that's nice.

The java binary is at /j9/bin/j9 which is a symlink to /mnt/ifs-root/j9/bin/j9, however that physical file appears to be inaccessible

(Script running with "set -x" - the "+" lines are the actual commands ksh is running)

Code:

JAVA_HOME is /j9
PATH is /j9/bin:/proc/boot:/bin:/sbin:/usr/sbin:/usr/bin:/j9/bin:/mnt/sdcard10t12/bin
+ ls -ovR /j9

/j9:
total 0
dr-xr-xr-x  2 root              0 Jan 01 00:01 bin

/j9/bin:
total 15
lrwxrwxrwx  1 root             23 Jan 01 00:01 j9 -> /mnt/ifs-root/j9/bin/j9
lrwxrwxrwx  1 root             36 Jan 01 00:01 java.properties -> /mnt/ifs-root/j9/bin/java.properties
lrwxrwxrwx  1 root             35 Jan 01 00:01 libiverel23.so -> /mnt/ifs-root/j9/bin/libiverel23.so
lrwxrwxrwx  1 root             34 Jan 01 00:01 libj9bcv23.so -> /mnt/ifs-root/j9/bin/libj9bcv23.so
lrwxrwxrwx  1 root             34 Jan 01 00:01 libj9dyn23.so -> /mnt/ifs-root/j9/bin/libj9dyn23.so
lrwxrwxrwx  1 root             33 Jan 01 00:01 libj9gc23.so -> /mnt/ifs-root/j9/bin/libj9gc23.so
lrwxrwxrwx  1 root             39 Jan 01 00:01 libj9hookable23.so -> /mnt/ifs-root/j9/bin/libj9hookable23.so
lrwxrwxrwx  1 root             34 Jan 01 00:01 libj9jit23.so -> /mnt/ifs-root/j9/bin/libj9jit23.so
lrwxrwxrwx  1 root             34 Jan 01 00:01 libj9jpi23.so -> /mnt/ifs-root/j9/bin/libj9jpi23.so
lrwxrwxrwx  1 root             34 Jan 01 00:01 libj9prf23.so -> /mnt/ifs-root/j9/bin/libj9prf23.so
lrwxrwxrwx  1 root             34 Jan 01 00:01 libj9prt23.so -> /mnt/ifs-root/j9/bin/libj9prt23.so
lrwxrwxrwx  1 root             34 Jan 01 00:01 libj9thr23.so -> /mnt/ifs-root/j9/bin/libj9thr23.so
lrwxrwxrwx  1 root             33 Jan 01 00:01 libj9vm23.so -> /mnt/ifs-root/j9/bin/libj9vm23.so
lrwxrwxrwx  1 root             35 Jan 01 00:01 libj9zlib23.so -> /mnt/ifs-root/j9/bin/libj9zlib23.so
lrwxrwxrwx  1 root             39 Jan 01 00:01 libjclfoun10_23.so -> /mnt/ifs-root/j9/bin/libjclfoun10_23.so
+ ls -ovR /java

/java:
total 1
lrwxrwxrwx  1 root             28 Jan 01 00:01 resources -> /mnt/ifs-root/java/resources
+ ls -ovR /mnt/ifs-root/j9/bin/j9
ls: No such file or directory (/mnt/ifs-root/j9/bin/j9)
+ ls -ovR /j9/bin/j9
lrwxrwxrwx  1 root             23 Jan 01 00:01 /j9/bin/j9 -> /mnt/ifs-root/j9/bin/j9
+ pwd

I was really optimistic it would be as simple as "j9 -cp $SDPATH/bin/ HelloWorld" (/j9/bin is already in path). I don't see anything special in the lsd.sh script itself, however it appears to be invoked in a special environment in /mnt/ifs-root/etc/mmi3g-srv-starter.cfg:

Code:

    <Process>
      <Number>63</Number>
      <Name>/lsd/lsd.sh</Name>
      <Args/>
      <ResArgs/>
      <Prio>10</Prio>
      <StartParam>BACKGROUND</StartParam>
      <OnTerminate>IGNORE_ALL</OnTerminate>
      <Shutdown>IGNORE</Shutdown>
      <ProvidesInterface/>
      <RequiresInterface>10</RequiresInterface>
      <RequiresInterface>56</RequiresInterface>
      <RequiresEnvironment>0</RequiresEnvironment>
      <RequiresEnvironment>1</RequiresEnvironment>
      <RequiresEnvironment>2</RequiresEnvironment>
    </Process>

Perhaps I'm missing something obvious?

Reply Like

12-30-2023, 03:52 PM

#34

drgertol

AudiWorld Member

Join Date: Aug 2011

Location: NW OH

Posts: 494

Likes: 28

Received 84 Likes on 78 Posts

@sm87 -- You discovered the next mystery of Harman-Becker's MMI3G/QNX implementation: that is, the case of the disappearing binaries.

After a few minutes of run-time, we find that certain binary files are no longer visible in the flash filesystem /mnt/ifs-root, including MMI3GApplication (and others in /usr/apps, /usr/bin/vdev-logvolmgr, and /j9/bin/j9 (and likely others).
Shell script /mnt/ifs-root/lsd/lsd.sh called by /mnt/ifs-root/etc/mmi3g-srv-starter.cfg is started relatively early in the start-up process -- inspection of the syslog shows the j9 process is started at around 5 seconds. A shell script run early enough (say, between 90 and 120 seconds of initial start) will show these binaries; after 3 minutes, they disappear from the filesystem. I don't know (yet) where this "feature" is described in the legacy QNX 6.3 docs.

Now, you can find the j9 JRE binary in the ifs-root.ifs image directly (extracted ZIP files listed here: https://www.audizine.com/forum/showt...1#post14904929). The JRE j9 binary is small enough to run from the SD card bin directory -- I would be curious to see if your "Hello, World" java class can be run from an SD card shell script (maybe rename j9 to j9jre so the QNX system doesn't try to make it disappear, too).

BTW, my initial motivation to poke at /mnt/ifs-root/lsd/lsd.sh and the MMI3GP J9 environment is described here: https://www.vwvortex.com/threads/mmi...roken.9520918/
I since found a fellow in PL who still had 3G mobile data access and a working myAudi account to collect some syslog information for a working HTTPS handshake and on-line destination download from the myAudi service -- work on this remains on my to-do list. --g

Reply Like

01-01-2024, 08:10 PM

#35

sm87

AudiWorld Junior Member

Thread Starter

Join Date: Jan 2014

Posts: 33

Likes: 1

Received 2 Likes on 2 Posts

Alright, so after a bunch more trial-and-error I finally managed to run some of my own java code on the MMI!

- Copy /j9/bin/* to the SD card.
- ~~Copy lsd.jxe to the SD card.~~ (EDIT: This is not necessary, can use the existing /mnt/ifs-root/lsd/lsd.jxe)
- Compile your .java code with "-target 1.4 -source 1.4" which requires an older JDK like Java SE 5 (JSE 6 or 7 might work)
- Run it like so (changing "HelloWorld" to your entry class):

Code:

$SDPATH/j9/bin/j9 -Xbootclasspath:/mnt/ifs-root/lsd/lsd.jxe -cp ${SDPATH}/bin HelloWorld

Figuring out "-Xbootclasspath:/mnt/ifs-root/lsd/lsd.jxe" was the tricky part, the entire JRE is packed onto that .jxe file starting from java.lang.Object and building on up. (I initially tried using rt.jar and friends from my local JDK but j9 seg faulted with those.)

Here are the options supported by the JVM:

Code:

[INFO] Running /mnt/sdcard10t12/j9/bin/j9 -h...
Licensed Materials - Property of IBM

J9 - VM for the Java(TM) platform, Version 2.3
(c) Copyright IBM Corp. 1991, 2006  All Rights Reserved
Target: 20060208_05219_lHdFGq (QNX 6.3.2 sh4)
JIT  - 20060207_1800_r8

IBM is a registered trademark of IBM Corp.
Java and all Java-based marks and logos are trademarks or registered
trademarks of Sun Microsystems, Inc.

Usage:	/mnt/sdcard10t12/j9/bin/j9 [options] classname [args...]
Usage:	/mnt/sdcard10t12/j9/bin/j9 [options] -jxe:<jxeFile> [args...]
Usage:	/mnt/sdcard10t12/j9/bin/j9 [-jxe] [options] <jxeFile> [args...]

[options]
  -classpath <path>
  -cp <path>       set classpath to <path>.
  -jxe:<jxeFile>   run the named jxe file.
  -jxe <jxeFile>   places jxeFile on the classpath and executes the startup
                    class found in jxeFile.
  -jxespace:<physicalAddr>,<size>,<logicalAddr>
                   map memory region for jxes, (values are in hex).
  -jxeaddr:<logicalAddr>
                   run a jxe directly from memory, (address is in hex).
  -D<prop>=<val>   set the value of a system property.

  -debug:<options> enable debug, JDWP standard <options>.

  -jcl:<config>[:options]
                   specify which JCL DLL to use (e.g. cdc, cldc, ...).

  -verbose[:class,gc,stack,sizes]
                   enable verbose output (default=class).

  -verify          enable class file verification.
  -X               print help on non-standard options.

[INFO] Running /mnt/sdcard10t12/j9/bin/j9 -X...
The following options are non-standard and subject to change without notice.

  -Xbootclasspath:<path>    set bootstrap classpath to <path>
  -Xbootclasspath/p:<path>  prepend <path> to bootstrap classpath
  -Xbootclasspath/a:<path>  append <path> to bootstrap classpath

  -Xrun<library>[:options]  load native agent library
                            (deprecated in favor of -agentlib)

  -Xint           run interpreted only (equivalent to -Xnojit -Xnoaot)
  -Xnojit         disable the JIT
  -Xnoaot         do not run precompiled code
  -Xquickstart    improve startup time by delaying optimizations
  -Xfuture        enable strictest checks, anticipating future default

  -verbose[:{class|gcterse|gc|dynload|sizes|stack|debug}]

Arguments to the following options are expressed in bytes.
Values suffixed with "k" (kilo) or "m" (mega) will be factored accordingly.

  -Xmca<x>        set RAM class segment increment to <x>
  -Xmco<x>        set ROM class segment increment to <x>
  -Xmn<x>         set initial/maximum new space size to <x>
  -Xmns<x>        set initial new space size to <x>
  -Xmnx<x>        set maximum new space size to <x>
  -Xmo<x>         set initial/maximum old space size to <x>
  -Xmos<x>        set initial old space size to <x>
  -Xmox<x>        set maximum old space size to <x>
  -Xmoi<x>        set old space increment to <x>
  -Xms<x>         set initial memory size to <x>
  -Xmx<x>         set memory maximum to <x>
  -Xmr<x>         set remembered set size to <x>
  -Xmrx<x>        set maximum size of remembered set to <x>
  -Xmso<x>        set OS thread stack size to <x>
  -Xiss<x>        set initial java thread stack size to <x>
  -Xssi<x>        set java thread stack increment to <x>
  -Xss<x>         set maximum java thread stack size to <x>
  -Xmine<x>       set minimum size for heap expansion to <x>
  -Xmaxe<x>       set maximum size for heap expansion to <x>

Arguments to the following options are expressed as a decimal from 0 to 1.
A value of 0.3 represents a request of 30%

  -Xminf<x>       minimum percentage of heap free after GC
  -Xmaxf<x>       maximum percentage of heap free after GC

Arguments to the following options are expressed a decimal numbers.

  -Xgcthreads<x>                set number of GC threads
  -Xnoclassgc                   disable dynamic class unloading
  -Xclassgc                     enable dynamic class unloading
  -Xalwaysclassgc               enable dynamic class unloading on every GC
  -Xnocompactexplicitgc         disable compaction on a system GC
  -Xcompactexplicitgc           enable compaction on every system GC
  -Xcompactgc                   enable compaction
  -Xnocompactgc                 disable compaction

  -Xdbg:<options>               enable debug, JDWP standard options
  -Xrunjdwp:<options>           enable debug, JDWP standard options
  -Xdbginfo:<symbol file path>  enable debug info server
  -Xrdbginfo:<host>:<port>      enable remote debug info server

[INFO] Launching /mnt/sdcard10t12/bin/HelloWorld.class...
+ /mnt/sdcard10t12/j9/bin/j9 -Xbootclasspath:/mnt/sdcard10t12/j9/lib/lsd.jxe -cp /mnt/sdcard10t12/bin HelloWorld
Java program is running!
Reading System.getProperties()...
Found 52 system properties:
  java.runtime.name=J9 - VM for the Java(TM) platform
  java.vm.version=2.3
  com.ibm.oti.configuration=foun10
  java.vm.vendor=IBM Corporation
  java.vendor.url=http://www.ibm.com/
  path.separator=:
  java.vm.name=J9
  com.ibm.oti.system.class.path=/mnt/sdcard10t12/j9/lib/lsd.jxe
  console.encoding=UTF8
  user.dir=/mnt/sdcard10t12
  java.vm.specification.name=Java Virtual Machine Specification
  java.runtime.version=2.3
  java.fullversion=IBM J9 2.3 QNX sh4-32  (JIT enabled)
J9VM - 20060208_05219_lHdFGq
JIT  - 20060207_1800_r8
GC   - 20060119_AA
  os.arch=sh4
  com.ibm.vm.bitmode=32
  java.io.tmpdir=/tmp
  line.separator=

  com.ibm.util.extralibs.properties=
  java.vm.specification.vendor=Sun Microsystems Inc.
  user.variant=
  os.name=QNX
  java.library.path=.:/proc/boot:/lib:/lib/dll:/usr/lib:/usr/lib/dll:/mnt/sdcard10t12/j9/bin:/lsd:/mnt/sdcard10t12/j9/lib
  jxe.current.romimage.version=9
  com.ibm.oti.vm.bootstrap.library.path=/mnt/sdcard10t12/j9/bin/
  com.ibm.cpu.endian=little
  java.specification.name=J2ME Foundation Specification
  java.class.version=47.0
  os.version=6.3.2
  com.ibm.oti.vm.library.version=23
  user.home=/
  user.timezone=GMT
  file.encoding=UTF8
  java.specification.version=1.0
  com.ibm.oti.configuration.dir=jclFoundation10
  enableVersionLabel=
  user.name=root
  java.class.path=/mnt/sdcard10t12/bin
  com.ibm.oti.vm.exe=/mnt/sdcard10t12/j9/bin/j9
  java.vm.specification.version=1.0
  java.home=/mnt/sdcard10t12/j9
  com.ibm.oti.jcl.build=20060208_1150
  user.language=en
  java.specification.vendor=Sun Microsystems Inc.
  java.vm.info=IBM J9 2.3 QNX sh4-32  (JIT enabled)
J9VM - 20060208_05219_lHdFGq
JIT  - 20060207_1800_r8
GC   - 20060119_AA
  my_custom_property=my_custom_value
  java.version=J2ME Foundation Specification v1.0
  java.ext.dirs=/mnt/sdcard10t12/j9/lib/ext
  jxe.lowest.romimage.version=9
  java.vendor=IBM Corporation
  file.separator=/
  java.compiler=j9jit23
  user.region=US
Checking file /dev/dsi/data...
 Exists: true
 Length: 0
 Can Read: true
 Can Write: true
 Last Modified: 70000
Opening FileInputStream...
java.io.FileNotFoundException: /dev/dsi/data
	at java.io.FileInputStream.<init>(Unknown Source)
	at HelloWorld.main(Unknown Source)

And so evidently /dev/dsi/data is part of the disappearing file conspiracy, hmm...

Last edited by sm87; 01-03-2024 at 08:32 AM. Reason: Updated -Xbootclasspath instructions.

Reply Like

01-02-2024, 05:54 AM

#36

drgertol

AudiWorld Member

Join Date: Aug 2011

Location: NW OH

Posts: 494

Likes: 28

Received 84 Likes on 78 Posts

Quote:

Originally Posted by sm87

...

Code:


	Code:
	...
Checking file /dev/dsi/data...
Exists: true
Length: 0
Can Read: true
Can Write: true
Last Modified: 70000
Opening FileInputStream...
java.io.FileNotFoundException: /dev/dsi/data
at java.io.FileInputStream.<init>(Unknown Source)
at HelloWorld.main(Unknown Source)

And so evidently /dev/dsi/data is part of the disappearing file conspiracy, hmm...

Well done. I wonder whether it is necessary to reference lsd.jxe from the DOS filesystem in the bootclasspath since lsd.jxe in /mnt/ifs-root is visible, for example:

Code:

J9=${SDBIN}/j9
export J9
$J9 -Xbootclasspath:/lsd/lsd.jxe -cp myjavaclass
...

In any case, I think your Java program finds special file /dev/dsi/data OK, but like cat, it can't open the resource because the earlier Java process owns it. I also think H-B made their DSI a service in the MIB system architecture so that multiple clients (including the UI & the pc tool) could access the DSI resource, as needed. Still, this is nice work. --g

Reply Like

01-03-2024, 08:27 AM

#37

sm87

AudiWorld Junior Member

Thread Starter

Join Date: Jan 2014

Posts: 33

Likes: 1

Received 2 Likes on 2 Posts

Quote:

Originally Posted by drgertol

Well done. I wonder whether it is necessary to reference lsd.jxe from the DOS filesystem in the bootclasspath since lsd.jxe in /mnt/ifs-root is visible

Good call "-Xbootclasspath:/mnt/ifs-root/lsd/lsd.jxe" works too, for some reason I got an impression the onboard lsd.jxe was absent/inaccessible (probably got /mnt/efs-system and /mnt/ifs-system mixed up looking for it).

Quote:

Originally Posted by drgertol

I also think H-B made their DSI a service in the MIB system architecture so that multiple clients (including the UI & the pc tool) could access the DSI resource, as needed.

I've yet to find anything that hosts an endpoint that we could talk to - if you have any pointers let me know. They definitely have facilities to mock various devices as TCP services, including replacing QNXTransport (which reads/writes /dev/data/dsi) with a SocketTransport, but that's for test/dev environments and doesn't help us. In case there's nothing existing available it seems possible to inject our own service/listener objects as part of the "startup bundle" to expose an endpoint.

Reply Like

01-04-2024, 10:34 AM

#38

drgertol

AudiWorld Member

Join Date: Aug 2011

Location: NW OH

Posts: 494

Likes: 28

Received 84 Likes on 78 Posts

Quote:

Originally Posted by sm87

...
In case there's nothing existing available it seems possible to inject our own service/listener objects as part of the "startup bundle" to expose an endpoint.

Interesting that you suggest that. Someone over on an a5oc forum just shared a "custom" HN+R_EU firmware that appears to be used to enable nav map display on certain A6/7/8 instrument cluster display units. The lsd.jxe blob has been "hacked" from the original HN+R_EU_AU_K0942 ifs-root.ifs image file (the custom JXE is about 8 MB smaller than the production version produced by H-B). But hacking the production JXE shouldn't be necessary if the listener object/service can be added as a separate JAR and added to the initial j9 configuration in /mnt/efs-system/lsd/lsd.sh. --g

Reply Like

01-06-2024, 12:58 PM

#39

sm87

AudiWorld Junior Member

Thread Starter

Join Date: Jan 2014

Posts: 33

Likes: 1

Received 2 Likes on 2 Posts

Quote:

Originally Posted by drgertol

I'm very hesitant about trying to modify the rom.classes in the .jxe without the proper tools on hand, maybe the EU folks have access to the legacy IBM J9 SDK. IBM handed off J9 to Eclipse and open sourced it as OpenJ9 circa 2017, could try that but no idea how well it supports the legacy versions, for instance looks like the standalone jar2jxe utility is gone now.

Anyway, lsd.jxe has this /resources/bundles.properties file that bootstraps the startup routine:

Code:

Bundle.Name.53=AppDevelopment
Bundle.Activator.53=de.audi.tghu.development.Activator
Bundle.Startup.Autostart=52,0
Bundle.Name.0=ATIPImpl
Bundle.Activator.0=de.audi.atip.base.Framework
...

Each index in Bundle.Startup.Autostart is processed like this:

Code:

Class activatorType = Class.forName(this.activator); // this.activator is value of Bundle.Activator.#
this.bundleActivator = (BundleActivator)(activatorType.newInstance());
this.bundleActivator.start(this);

So basically the plan is:

Implement org.osgi.framework.BundleActivator interface - just start() and stop() - which spin up a service endpoint for us to use later. (Just ServerSocket is available so implementation would be pretty low level, but no big deal)
Make the compiled .jar/.class files available to runtime, lsd.sh adds a "-Djava.library.path=.:/proc/boot:/lib:/lib/dll:/usr/lib:/usr/lib/dll:/j9/bin:/lsd" option so copying it to one of those dirs ought to be fine (since the type will be late-bound)
1. Another option is to hijack /lsd/TestServer.jar or /lsd/xEventRecorder.jar file paths which the script already probes (it also checks /lsd/DSITracer.jar which seems to exist).
Update bundles.properties:
1. Either update lsd.jxe/resources/bundles.properties (a text file in a zip archive - easy).
2. Uncomment/add this line in lsd.sh #VMOPTIONS="$VMOPTIONS -Dlsd.bundles=$BASEDIR/bundles.properties" which will take precedence over the embedded resource. Since lsd.sh does not initialize the VMOPTIONS variable possibly set VMOPTIONS="-Dlsd.bundles=$BASEDIR/bundles.properties" at the system level.

All the startup steps are diligently wrapped with try/catch so it should be relatively safe to experiment with. One snag for the moment is the jxe2jar script fails to convert some of the .class files which will be needed to compile the custom bundle (e.g. BundleActivator). Also the major .class versions in the .jxe are all over the place ranging from 20 to 28244 (considering the time period it they should be 45-48), may be some form of obfuscation?

Reply Like

The following users liked this post:

drgertol (01-06-2024)

01-21-2024, 09:59 AM

#40

drgertol

AudiWorld Member

Join Date: Aug 2011

Location: NW OH

Posts: 494

Likes: 28

Received 84 Likes on 78 Posts

@sm87 -- Check out this thread from one of the forums on a5oc: https://www.a5oc.com/threads/upgradi...imedia.180005/

This fellow from ~~Romania~~ Lithuania put together a big system patch to convert an MMI3G High (HNav) system into the functional equivalent of an MMI3G Plus (HN+) system.
No word yet if his patch can be applied to HNav_US systems, but this is potentially a very-big-deal, IMO. --g

Last edited by drgertol; 02-17-2024 at 08:31 AM.

Reply Like

The following users liked this post:

sm87 (01-21-2024)

Reply Share

First
Prev
4 / 8
Next
Last