wrm

The $25 Network

These days one can network a bunch of computers for $25 without breaking much of a sweat, since most if not all computers these days come with a network port right there on the motherboard, and if it’s a notebook there will be wi-fi right there as well.

But back in 1987 networks were a big deal. Arcnet came out in 1982 and Ethernet was standardized in 1983 — using almost-a-centimeter-thick coax cables with the delightfully named “vampire tap” connecting stations to the backbone. Yes, we’ve come a long way.

So being able to network two or three machines for $25 was a Big Deal. At around the same time you could get two Ethernet adapters and a cable from LANtastic for $699.

How? Point-to-point serial cables, with one machine acting as a hub in three-machine installations. According to the documentation, this is good for 80 feet at full speed (115 kbit/s). This and some very clever DOS software from D. Jindra and R Armstrong, calling themselves Information Modes and operating from a drawer in Texas. All drives (which in 1987 meant 360k to 1.2Mbyte floppies, and maybe a 20Mbyte hard drive somewhere) and printers could be accessed from all the machines in this network.

It was magic, I tell you. Kids of today, they don’t believe a word of it.

 

  • Link to the files I have (Time has not been kind. There’s some bitrot in the filenames I think)
  • The Data Packrat has a disk image of a different version of the $25 Network and delightfully odd ideas of how the internet works.

 

Kenwood TK-2000 password

A tale of how not to do it, with a happy ending.

Our hunting club has eight Kenwood TK-2000 walkie-talkies. This is hardly ever enough, even when I take my Baofeng UV-B5* with.

So when a fellow ham had two TK-2000s for sale, I bought them. The programming cable is easy, and the software (KPG-137D) is not hard to find.

The first radio programmed fine, the second one… is password protected. I’m sure there’s a trick to resetting the password, I just don’t know what it is. So out comes the schematic from the service manual, and there’s an EX24016 hanging off the side of the R5F2136A microcontroller. EX24016 being another way of saying 24C16 which is an EEPROM. Memory. Where things get stored.

And while my favourite programming language is not solder, I’m not half bad at it.

And one universal programmer and one of my favourite tools later we have (the bits not shown are all just FF).

OK, so what does this mean? Stumped me too. The stuff at the end is self-explanatory, it’s a TK-2000 and the serial number of this one is B1104749. I’m pretty sure it’s on the same frequency as the other one, that would be one channel only, 169.43750 with a 103.5 Hz subtone, high power, narrow band. Oh look, right at the start there’s a sequence of bytes, 50 37 94 16 repeated twice. Back to front, transmit and receive frequencies. Given enough time one could decipher the whole thing, but that’s not important right now. We need the password.

The KPG-137D help file tells me that there are two passwords, one to allow you to read the data and the other for writing.  The password is a number from zero to 999999 (six digits). This eliminates a whole bunch of hopefuls like “PTK-2000” or one of those long strings at 1824/1840.

So I stuck the EEPROM back into the radio, wired the cable up, and started guessing. I had some hope for “222222”, for example. But no, it wasn’t going to be that easy.

So I thought, maybe the KPG-137D software “knows” what the password is. In other words, is the password sent to the transceiver, or checked on the local machine? I’m not expecting strong security here. I wired a second serial port to eavesdrop on the datastream (19200 N81) and saw that there’s no traffic on the line while I’m guessing passwords. So I tried looking on the heap of the KPG-137D but I suspect the password is stored as a number, not as text, no joy there either. There’s a lot of data on the heap and anything could be the password. Someone who knows Windows better than I do would be able to trap this thing at the right place and get the password.

Next I hauled out my working transceiver, and eavesdropped the datastream with different passwords set (I started with 000000, 000001, 000002). I noticed that the first 52 bytes of a read are the same and that after that things change.

Password Bytes 53-56 Binary
000000   AC B3 AF AD 1010 1100 1011 0011 1010 1111 1010 1101
000001   B8 A7 BB B9 1011 1000 1010 0111 1011 1011 1011 1001
000002   A9 B6 AA A8 1010 1001 1011 0110 1010 1010 1010 1000
                     ^^^  ^ ^  ^^^  ^ ^  ^^^  ^ ^  ^^^  ^ ^

Note the columns that stay the same in the binary. This suggests that old favourite, XOR encryption. The only problem is that I’m changing two bits in the password and three bits are changing in the data, which suggests some other nefarious seekrit manipulation.

With enough sample cases, I can figure it out, I’m sure.

Time to try something else. I didn’t really want to potentially break my working transceiver, but desperate times. Yup, I ripped the EEPROM out of that sucker and read it as well.

Byte 16 is “0A” instead of “FF” and bytes 22/23 and 25/26 is “FF FF” instead of “56 91”. That’s the first difference in the EEPROM, might as well start there. I first converted 0x5691 and 0x9156 to decimal, that didn’t work, but plain old “5691” did. I would have put money on “9156” being more likely to work than “5691”, based on the frequency being stored arse-endian, but no.

So there you have it. If I’d tried enough numbers from the EEPROM instead of giving up after not finding the password in plain text, I would have been there a lot earlier.

* A cheap and nasty, but extremely versatile little radio. Does VHF and UHF amateur bands, PMR and FRS, marine… you can get yourself into all kinds of trouble with this thing.

 

Be vewy quiet…

If you wear camo and sit very quietly in the shade of a bush you can get to see interesting things.

See it? Lemme zoom in a bit for you.

I sat watching this fellow as he was making a beeline pretty much straight for me.

This is a split second after he saw me (the camo in the foreground is me). Changed his mind pretty quickly and made for the hills.

And the evening I had to eat a gemmerkoekie* as punishment for not shooting the blighter. Because there are two problem animals that get shot on sight on farms, jackal** and caracal***.

Why didn’t I shoot? The gemsbok were just behind that ridge ahead of me, and I was seriously considering changing my priority from kudu to gemsbok. That ended up not happening and I walked-and-surprised**** a nice young kudu bull the next day. So all turned out well.

* “gemmerkoekie” = ginger biscuit. But laced with Stroh rum. I like Stroh rum. This is a game I play to lose.

** Black-backed jackal, known as “rooijakkals” or red jackal in Afrikaans. The little bat-eared foxes and silver foxes are also “jakkals” in Afrikaans but you don’t shoot those.

*** I don’t think I’ll ever be able to shoot a caracal. And of course the african wild cat is rightly so a no-shoot.

**** You don’t walk-and-stalk a kudu. You walk-and-surprise it. It will see you before you see it, if you’re moving, and it won’t stay around for too long. And once they’re gone, they are gone. Over the mountain, down the other side, over the next mountain, and still going strong, while you’re still trying to find your second wind.

The war that didn’t end all wars

100 years ago, it seems that everyone all over Europe was itchy as all hell, and all that was needed was a tiny spark.

Enter stage left, a troop of idiots students* who figure that killing the Archduke Ferdinand would be a just dandy way of getting the sweetties they’ve been stamping their foot about all along. This crazy is well matched on the Archduke’s side, who after being narrowly missed by a bomb in the morning sticks around town instead of getting the hell out**.

And even then all would have been well for Franz Ferdinand had they not got lost to the tune of accidentally finding Gavrilo where he sat nursing a cup of coffee, a grudge and a gun.

Not that anyone much cared.

But Europe was spoiling for a fight, and the finger poking and name-calling and posturing escalated. Germany had a long-polished plan to invade France which, by all accounts, it didn’t really want to use at the time, but then France went and tweaked Germany’s tail and then the trouble started.

Or at least, that’s how we mostly see things. Because history is written by the winners.

Nevertheless, the result was major bloodshed. Would they really have done it had they known what the price would be?

Photo: Wikimedia Commons

100 years later, and there’s still no end to itchy idiots, military posturing or war.

Remember.

 

* Repeating myself, of course.

** In the finest tradition of some authors whose work I like, I will mention that the whole story is exquisitely explained on Wikipedia, for the low low price of free.

Booyah!

I absolutely have to repost three videos my buddy Weer’d found while I was away playing hide and seek.

“So, in summary, firearms have (at worst) an immeasurably small causal effect on violence, violence is a systemic problem in certain communities, and focusing on singular horrible events because of media buzz is a nasty, racist attempt to deflect attention from the real causes, because those causes are embarrassing, and because certain useless symbolic actions look good.

“The idea that the police are not civilians is a deeply pernicious, dangerous one, and it is demonstrably false.

“The truth is a set of not-too-exciting little details, not a cute soundbite.

“Now of course, and I want to emphasize this, cops’ lives and jobs can be dangerous, and I want them to be able to defend themselves vigorously and successfully when that need arises. But when we define them by that armed conflict role, when that becomes their most salient characteristic, well, no good comes of it.

This third video doesn’t pack nearly the punch of the other two, but it does explain the firearm licencing process in South Africa quite accurately and quite well.

 

 

Thirty years later…

… I still think it’s a bloody good movie.

http://youtu.be/y-YHw1sqjL8

Here’s an interview for you.

The final act of ‘Top Secret!’ spoofs ‘The Blue Lagoon,’ a 1980 film starring Brooke Shields and Christopher Atkins — a film that was the ninth highest grossing film of 1980, but hasn’t retained a strong presence in popular culture today. Despite the disparity of their original box office totals, today ‘Top Secret!’ is a more popular film than “The Blue Lagoon.’

Frosty

We don’t often get really cold weather. The first cold front of this winter was the exception.

I used some isopropyl alcohol to defrost Tanya’s windscreen, my car I just started up, turned the demister to full, and let it idle for ten minutes.

I also saw some frost on the grass next to the M3 in Tokai.

This is about as bad as it gets in Cape Town, temperature wise. That’s why we like it here :-)