Sharp PC Cartridge Adapter Board

April 8, 2015July 25, 2015 / Kai / Leave a comment

The following cartridge adapter board completes my already presented series of Sharp PC adapters: my Interface and my Cartridge.

The Sharp PC-1500 and PC-1600 can both be extended via one (two) module slots. Pretty common are memory extension cartridges, but there are also more sophisticated modules. I have a few that contain an (E)EPROM with program code on it. I have a few of the latter ones and to facilitate reading out their content I’ve built an adapter board:

The 40-pin connector was cut out of a regular PCI slot (not PCI Express). You can actually get two connectors out of one slot.

Pin headers allow easy access to the data, address, and control lanes of the cartridge. In many cases this allows easier debug access to the content of a cartridge (it EPROM) than reading (i.e. ‘beeping’ out) its content directly via the PC-1500/PC-1600 + PC-150 interface.

The adapter board works for me but it can be pretty annoying to get the pads of a module aligned with the connector pins in the 40-pin slot. It usually takes me a few retries to get good contact on all pins. Some kind of guide rail on both sides would be helpful, but hey, it’s a hack… 😉

Watched the Solar Eclipse with a Quick and Dirty Pinhole Camera

March 20, 2015July 25, 2015 / Kai / Leave a comment

Of course neither me nor any of my colleagues had an appropriate protection to view the upcoming solar eclipse. So I had to ‘hack’ together a device to still be able to watch the eclipse pass in a safe manner.

Solar Eclipse (Munich, Germany, 2015.03.20 10:40 CET) viewed though a simple (5 minute hack) pinhole camera:
The camera was built from an old rolled conference poster, some adhesive tape, plastic foil, and a cardboard box. I think it is self-explanatory:
One side was covered with opaque foil, only a tiny pin hole (< 1 mm) let light through. The other side was simple plastic foil (from my lunch). The box acted as a shield to protect from accidentally looking into the sun.

It’s a mirror image, by the way.

Additionally (out of curiosity) I’ve taken a photo with my iPhone 4S:
The eclipse can be seen in the lense flare (here a 100% cut-out):

Kabel Deutschland TR-069 Auto-Configuration on a FritzBox 7390

March 3, 2015December 10, 2015 / Kai / 1 Comment

The cable provider Vodafone (Kabel Deutschland) does not officially support VoIP connections from other routers than the ones they have issued: in my case a FRITZ!Box 7270. They do not provide the VoIP credentials; their boxes are auto-configurated via TR-069 protocol. Having a FRITZ!Box 7390 led me to investigate how to enable this full auto-configuration in other boxes than the 7270.

This is a follow-up to my previous post on how to clone CWMP settings between FritzBox 7270s.

I started with a freshly recovered FritzBox 7390, i.e. all previous configuration settings were erased. Also I did not connect any devices to the FritzBox. The Power/DSL LED is blinking.

The following changes were made via the UART interface on the PCB. I have not tested them via the FritzBox Telnet connection. It might be possible to write and trigger them as a shell script (as the network connection is shut down in the process), I have not tested that either.

Start with a shell on the FritzBox and shut down the network and DSL daemons:

cd /etc/init.d/

./rc.net stop
    [...takes some time...]

./rc.dsl.sh stop
    [...takes some time...]

Then reconfigure the environment settings. I’ve used the urlader / boot loader (EVA) to set the tr069-credentials (as described here). I’m not sure if they can be also defined later, but if so, it should look something like this:

echo "tr069_passphrase XXXXXXXXXXXX" >> /proc/sys/urlader/environment
echo "tr069_serial 00040E-XXXXXXXXXXXX" >> /proc/sys/urlader/environment

You might also want to check the MAC addresses: maca, macb, macwlan, macwlan2, macdsl, usb_board_mac, usb_rndis_mac
If the default addresses are set the FritzFox might completely fail to establish an internet connection. You then should set them to (pseudo)random values.

The following settings have to be adapted temporarily to simulate a FritzBox 7270. These environment variables will be reset on the next reboot (unlike the changes in the urlader, btw.). The remote TR069 server is checking the product name and the software version (besides the previously defined tr069-credentials).

export CONFIG_PRODUKT_NAME="FRITZ!Box Fon WLAN 7270 v2"

export CONFIG_PRODUKT="Fritz_Box_7270_16"

export CONFIG_VERSION="06.05"

export CONFIG_SUBVERSION=""

export CONFIG_VERSION_MAJOR="54"

export EXTERNAL_BOX_PARAMS="hardware=${HWRevision}&oem=${OEM}&language=${Language}&country=&version=${CONFIG_VERSION_MAJOR}.${CONFIG_VERSION}&subversion=${CONFIG_SUBVERSION##*-}"

After that restart the network settings:

./rc.net start
    [...wait 10-20 seconds...]

Connect the FritzBox to the cable modem (via LAN1). After a while the FritzBox should fetch the CWMP/TR069 settings, including the telephone settings. This can be checked by entering:

 cat /var/flash/tr069.cfg
     [...should list tr069 settings...]

cat /var/flash/voip.cfg
    [...should list telephone settings...]

P.S. I recommend to disable the TR-069 auto-configuration settings if not needed. They theoretically poke a quite huge hole into the security of your router.

Cloning FritzBox 7270 CWMP Settings

February 2, 2015July 25, 2015 / Kai / 1 Comment

I own an over 5 years old AVM FritzBox 7270 router which is after all that time becoming slightly unstable. (The capacitors might be wearing out.) The router uses the CWMP (TR-069) protocol to authenticate itself at my cable provider Vodafone (Kabel Deutschland). As these settings are tied to the box and the FritzBox 7270 is neither sold nor supported anymore I bought two cheap 7270_v2 boxes (identical hardware, different branding) on eBay and successfully transferred the authentication credentials from my old box onto the two new ones.

Warning: Please keep in mind that the following steps worked for me but I do not feel responsible if you brick your FritzBox by trying them out yourself. I tested it on two spare routers I’ve explicitly bought for this purpose.

0. Debranding & serial connection

Opening the cases of the routers allowed direct access to the serial interfaces on the PCBs. This might not be necessary as all (following) steps, at least the debranding (here: “1und1” to “AVM”), can be done without access to the serial interface. I have not tested that. But the serial interface allowed the “deepest” access to the routers’ system.

I will not describe how to set-up a terminal connection and how USB to RS232 adapter work. This is sufficiently covered by other tutorials. It is also not necessary to solder pins onto the RS232 interface on the PCB. For me it worked perfect to just stick a few pin headers into the pads as seen on the following two images. (It’s best to not touch the cable during the process though.)

1.Test: Directly connecting the two new boxes to the cable modem

After a factory reset (“Werkseinstellungen”) via the web interface I’ve first connected the two boxes to the cable modem. As expected they were able to fetch the general provider settings but not the VoIP (telephone) settings.

Comment: The VoIP settings can be extracted by hand from a fully authenticated FritzBox but I wanted them to also do that for me.

2.Backups: Storing the environment settings and MTDs

It is always a good idea to make backups of the devices you are going to hack. I attached an USB stick to the box and changed into a newly created directory on it. You will need to backup the following file on all of your FritzBox routers. (Adapt the destination filename as necessary.)

cp /proc/sys/urlader/environment environment-source-fritzbox.txt

It’s also a good idea to make backups of the block devices… just in case. (The FritzBox 7270 there should have 6 block device “mtd0” to “mtd5”.)

dd if=/dev/mtd0 of=mtd0.bin

3.Cloning the CWMP settings

I once again ran a factory reset while having the serial interface connected to the box. I halted the boot process directly after the reset when the bootloader (“urlader” / Eva_AVM) appeared. The bootloader shows a prompt for 5 seconds and the boot process can be interrupted by entering a command, e.g. “h<enter>” for help.

[...]
system is going down ..
The system is going down NOW!
Sent SIGTERM to all processes
Requesting system reboot

(AVM) EVA Revision: 1.455 Version: 1455
(C) Copyright 2005 AVM Date: Apr 1 2008 Time: 13:07:03 (1) 2 0x0-0x41D

[FLASH:] ST Uniform-MirrorBit-Flash 16MB 64 Bytes WriteBuffer
[FLASH:](Eraseregion [0] 128 sectors a 128kB) 
[SYSTEM:] UR8 on 360MHz/120MHz syncron

 Commands Description
 -------- -----------
 help help
 dm dump mem <addr> <range>
 cm change mem <addr> <value>
 erase Erase Flash <mtd>
 printenv print Env. Variables
 restart reboot Device
 setenv set Env. variable <var> <value>
 unsetenv unset Env. variable <var>
 go load & start kernel from mtd1
 setmac set mac addresses <addr> (like 12:23:40)
 memtest test memory

To really erase all settings from the FritzBox 7270 I’ve used the “Erase Flash” option. The settings are stored in two TFFS blocks: mtd3 and mtd4.

Warning: stay away from mtd2 (the bootloader)! Erasing this block device will brick your router.

Eva_AVM >erase mtd3
erase from 0x90F80000 to 0x90FC0000

Eva_AVM >..
Eva_AVM >erase mtd4
erase from 0x90FC0000 to 0x91000000

Eva_AVM >..
Eva_AVM >restart
<create new TFFS>

[...break here! ...]

After a restart the TFFS partitions are recreated based on the hardcoded settings in the bootloader. Again interrupt the boot process directly after the TFFS blocks were restored. Now you have to look into the previously stored environment settings from the original FritzBox and add (or overwrite) the CWMP settings in the destination box. It might be necessary to also set the MAC addresses as they might have been set to default values. (The default MAC addresses possibly won’t let you connect at all – I’ve had that problem with one of my boxes.)

Eva_AVM >setenv tr069_passphrase XPASSPHRASEX

Eva_AVM >setenv tr069_serial 00040E-XXXSERIALXXX

Eva_AVM >restart

Comment: You can check with the “printenv” command if the settings were successful and if the default environment (MAC) settings were set.

Eva_AVM >printenv

In my case that was all I had to do. I then let the router boot as normal and connected it to the cable modem. After a minute or so it fetched all necessary settings (including the VoIP settings) and pre-configurated the FritzBox.

Surprisingly it was not necessary to transfer the MAC addresses or any other settings from the original FritzBox to the other two boxes. (Something I expected based on various forum posts.).

I’ve later also tried the same steps on a FritzBox 7390 but failed to receive the VoIP settings. The ProductID (FritzBox 7270) and the software version is additionally transmitted along with the tr-069 credentials. In a second post I’m providing a possible solution on how to achieve an auto-update via TR-069 on other FritzBoxes.

Sharp PC-1500 Cartridge for debugging

November 16, 2014July 25, 2015 / Kai / 5 Comments

For debugging purposes (and also for playing around with memory chips on a bread board) I’ve created little breakout boards for the cartridge slot on the bottom of Sharp PC-1500s/1600s.

I’ve added a layer of foam (not visible on the photo) on the bottom side of the cartridge to prevent the pin ends from scratching on the case.

Typing on the PC while having cables connected to the cartridge is a bit annoying as I tend to pull off the cables when turning the PC around. I’m currently figuring out a better solution by using ribbon cables instead of the pins. I will update the post as soon I’ve managed to make photos of the modified version.

Sharp PC-1500 Interface Card / Breakout Board

November 16, 2014July 25, 2015 / Kai / 3 Comments

Just a little update for all readers interested in Sharp 1500/1600 PCs: for hacking around with the Sharp Pocket Computers I’m using a self-made breakout board that allows easy access to all 60 pins of the interface connector.

The 60-pin connector is a simple 1.27*2.54 60-pin male header (I’ve bought mine here).