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Messages - QwazyWabbit

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1201
0x1337c0de / Re: Questions on General Software Design.
« on: March 07, 2008, 08:47:52 PM »
oh and could someone explain bit significance and byte ordering like little endian and so on...

Endianness is a property of the CPU architecture. It can refer to bits or bytes, although it's rare to see it referred to bits these days. In the days of minicomputers like the PDP-8 bit 15 was the least-significant bit (the one on the right) and had the value 2^0 and bit 0 had the value 2^15 and was on the left. (Left and right were the on the register panel and the toggle switches below it.) The PDP-8 was actually a 12-bit machine (bits 0 thru 11) but had extensions on the memory address to add 3 more bits to the most significant end of the address. The PDP-8A control panel had switches on the front panel for toggling in the programs. This front panel was later emulated on the MITS Altair 8800 that had a Intel 8080 microprocessor in it. In the case of the microprocessors, bit 0 was on the right, value 2^0 and bit 8 or bit 15 were on the left for registers or addresses. The endianness of the bit values were the same but when referring to the bit number the endianness was reversed. I don't think the PDP-8 had any bit-address mode instructions but if you referred to bit 7 in PDP-8's it's value was 2^8 or 256 vs. 2^7 or 128 in 8080's or any microprocessors that came later.

Little endian bit index order and enumerating them from right to left makes more sense because the bit address (offset) corresponds to the power of 2 it represents. Offset 0 is 2^0, offset n is 2^n.

Offset refers to the position of a byte in a file or memory block. The first byte has offset zero, or is the zeroth byte in the block, then offset 1, 2, 3 , etc. until offset n-1, n for any n items in a list. An offset refers to the order of the items in a list, the list could contain bytes, words, or double-words or could even be structures of bytes. Programmers always call offset of the first item in a list as offset zero. Some older computer languages allow counting to begin at 1 instead of 0.

Endianness in byte order refers to the way the bytes are stored in memory or even transmitted serially. If ABCD represents 4 bytes, then on little-endian machines they are stored in memory as DCBA where:

Offset    Byte
   0           D
   1           C
   2           B
   3           A

On big-endian machines they are stored as:

Offset    Byte
   0           A
   1           B
   2           C
   3           D

This is great when sending bytes serially since you can walk right down the list and they will be transmitted exactly as they are stored in memory as bytes and they will "read" left to right in this fashion. This is why big-endian was chosen as network byte order in the early days of the Internet. (The first networked computers were big-endian.)

This doesn't apply to byte strings however. Strings are always stored in memory from lowest to highest address first character to last character regardless of the endianness of the computer. It's only when you start talking about multi-byte values that it gets interesting.

Take the 16-bit example. If AB and CD represent the bytes of two 16 bit integers, the little endian machine will store them as:

Offset    Byte
   0           B
   1           A
   2           D
   3           C

The big-endian will store them as:

Offset    Byte
   0           A
   1           B
   2           C
   3           D

Storing or transmitting them from a big endian machine to a little endian machine must take this into account and they must know the nature of the data they are trying to transmit.

1202
Trouble Shooting / Re: r1q2 and downloading maps
« on: March 02, 2008, 06:00:43 PM »
By my count, there are 48 original maps in Q2. The first group of 45 is in pak0.pak with the others in pak1 and pak3 as listed in comments below.

static char *stockmaps[48] = {
   "base1", "base2", "base3", "biggun", "boss1",
      "boss2", "bunk1", "city1", "city2", "city3",
      "command", "cool1", "fact1", "fact2", "fact3",
      "hangar1", "hangar2", "jail1", "jail2", "jail3",
      "jail4", "jail5", "lab", "mine1", "mine2",
      "mine3", "mine4", "mintro", "power1", "power2",
      "security", "space", "strike", "train", "ware1",
      "ware2", "waste1", "waste2", "waste3", "q2dm1",
      "q2dm2", "q2dm3", "q2dm4", "q2dm5", "q2dm6",
      "q2dm7", "q2dm8", // pak1.pak
      "match1" //pak3.pak
};

There was a demo version of Q2 circulating at one time. I am not sure if it was official or not. I know several users showed up intermittently on servers and they didn't have certain maps. I remember one user was missing "mintro" in her demo, not sure how many other maps might have been missing as well.

1203
/dev/random / Re: Separated At Birth
« on: February 17, 2008, 11:10:14 PM »
hmmmm.... hirsute and no ears. Highly suspicious.

Who's been banging on the windows with a hammer anyway?

Girls go crazy 'bout a sharp dressed man.

1204
Tech Junkie Lounge / Re: Tech Junkie Quotes
« on: February 17, 2008, 01:00:25 AM »

  Debugging is twice as hard as writing the code in the first place.
  Therefore, if you write the code as cleverly as possible, you are,
  by definition, not smart enough to debug it. -- Brian Kernighan


Hard not to love it when it rings so true.



Write code as if an idiot will be debugging it a year from now.
A year from now that idiot will be you. -- QwazyWabbit


Curse the smartass that wrote this impenetrable piece of code last year. ;)

QW

1205
Tech Junkie Lounge / Re: Vint Cerf
« on: February 04, 2008, 10:14:06 AM »
I liked perl, it's very much like a high-level C and it's great for smallish programs that one person can manage. Unfortunately I kind of burned out on it doing web backends for a friend who promised to pay for some urgently needed stuff and learning Perl against a deadline or under delivery pressure is not fun. Left a bad taste when the pro quo fizzled. I deal with it. :) I do small stuff for myself from time to time. Another feature of perl's pedigree is the cult of anti-cultists who surround it in the newsgroups. Submit code to the comp.lang.perl group at your own peril. They will call it cargo cult, lame, rip it to shreds even when it came from something previously posted as good stuff. Perl at the time I was learning it was still evolving, if it was written yesterday it's obsolete cargo-cult today. Yesterday's detainting is today's vulnerable code.

Ruby sounds like fun. I will have to find some time to look at it more closely.

Java is becoming the code du jour. It's in my Blackberry and seems to do the job nicely. I need to browse for some open source stuff for the BB, maybe a nice RPN calculator like my HP48. :) hmmmmm color graphics....  :bigshades:


1206
Tech Junkie Lounge / Re: Vint Cerf
« on: February 03, 2008, 09:06:00 PM »
No system made by man is perfect. There will always be a flaw that can be exploited. -end philosophic platitude-

Seriously, programming languages are evolving and getting better at being good tools and not providing implicit attack points.

C was conceived before there was a substantial Internet. A program could trust its own data. The only danger to a UNIX box was it's users. UNIX as it was implemented had all kinds of flaws that if you placed a naked unix box on the net today, it would perish as fast as any Windows box. There is nothing wrong with the C language itself, it has all the constructs needed in most programs. There were some compromises made back when the ANSI standard was being set and the "standard library" was being defined that led to some pretty stupid decisions and implementations in the library that made it hard to not make mistakes or that automatically created some opportunities for exploitation. Those decisions were made by the commitee seeking compatibility and breaking the least amount of existing code, they weren't very security concious at that time. At the same time nothing prevents a programmer from designing his own library focused on security and ease of use and correctness. Perl, PHP and Python were written in C, IIRC, and fundamentally use the standard C library at their core.

As for sendmail, it's almost as ancient as UNIX itself. It's old and complex and if it still has vulnerabilities it's probably because it's hard to maintain. I have never looked at it's code but I would imagine it has some places that could stand some good security review.

Language selection is based on requirements or personal preference. I can almost write a C program faster than I can in Perl. That's because I know C a little better. My Perl programs tend to be a little C'ish and I will sometimes make some idomatic mistakes.

Java is a good tool but the programs tend to be slow for the same functionality in a compiled language like Perl or C. The trouble I have with JVM, MFC, and the managed code libraries like the .NET framework is that you are dependent on a library you know almost nothing about, can't fix, can't maintain, can't snoop, and can't do without. You become a library junky. Dependent on a junky library. How many JVM versions are there? What did they fix and why? (See buffer overflows.) Sun has made JVM deployment mistakes all over the place and it's a PITA.

A good programmer writes his own libraries or at least organizes his functions in such a way that he can re-use them to build better programs. If you don't like malloc()/free() you can write your own. :) Good luck. Java takes that right away from you. They don't call it garbage collection for nothing. I remember coding in BASIC on the TRS-80 I in 1977 and watching my program stall suddenly while the BASIC interpreter collected garbage. We have not gone that far, really.

Anyone read the coding standards manual for the JSF recently? FYI, flight systems code is in C++. :)

1207
Quake / Re: Railgun meets real life.
« on: February 02, 2008, 10:51:14 AM »
Looks good! Time to buy some Encabulator stock and get in on the ground floor of some amazing technobabble. :)

1208
Quake / Re: Railgun meets real life.
« on: February 01, 2008, 07:07:35 PM »
Here's the straight skinny on the RG from the lab, without the brain-dead filtration by the newsies.

http://www.onr.navy.mil/emrg/electromagnetic-railgun.asp

It's been in development quite a while. Getting it down to a deployable weapon from a research tool is the key.

In this test 2520 Meters/sec. muzzle velocity = Mach 7.6  or 8267 feet/sec.

10.6 MJ is only 2.94 kilowatt-hours but the peak power and power density in the weapon leads to intense temperatures in the bore. You have to have mass in the weapon to dissipate the heat and to survive the kickback. (Not a good handheld weapon.) Newton's laws still apply. (F = ma = d(mv)/dt)

The mass of the projectile was 3.520 kg according to the video. You need to know the length of the rifle to know the acceleration but it looks about 3 meters long. 3/2520 = 0.00119 secs or 1.19 milliseconds to go from 0 to muzzle velocity.
3.52 kg x 2520 m/s / 0.00119 s = 7454117.6 kg-m/s^2 (Newtons) or about 1.676 million pounds. Quite a kick.

You might have a nice K.E. weapon as a "needler" from SciFi novels. Something low mass like a 10mg needle at those speeds would do some damage. You might be able to create a rifle with a backpack power supply but then you would need another soldier to carry all the other gear they both would need. Great if you are sniper team. :)

From the paper, reading between the lines, it looks like the big techno hurdles are pulse generator design and material science on the projectiles and the bore. The intense heat and friction makes for some awesome erosion, I would imagine. Another factor would be moving all the air in front of the projectile out of the muzzle. That's why it's got such a huge muzzle flare. That's all just ionized gasses from the displaced air.


1209
Quake / Re: Anticheat for linux
« on: January 19, 2008, 05:14:28 PM »
Dang. I was looking forward to a nice flame war and religious debate and he agrees with me in the first round.

I am just going to have to go back to lurk mode and buy a tee shirt.

1210
Quake / Re: Anticheat for linux
« on: January 19, 2008, 12:15:23 PM »
Quote from: X'tyfe on January 19, 2008, 07:22:43 AM
Quote from: X'tyfe on January 19, 2008, 07:22:43 AM
i would like to point out that CHEATS AND HACKS DO NOT EXIST FOR LINUX
that is all :)

Patently false assertion.
Model spikes and hacks will work with Linux just as well as in a Windows client. These are what AC was intended to detect.
Brightskins work in Linux as well as Windows. They are not OS dependent.
Gloom depends on certain client variables remaining in specified limits. These can be tweaked in Linux as easily as in Windows. There is no method to verify the variables are within those limits except for a mechanism like AC.
Anyone with bot sources can build an aimbot for the Linux clients.
Anyone with Linux skills is more likely to have access to cheat sources and be skilled enough to use them, perhaps more skilled than some Windows users who just load the stuff and need to be spoon fed the tools.

Using a Linux client does not automatically confer "Purity of Code".

QW

1211
tastyspleen.net / Re: Creation of a tastyspleen LoX server?
« on: January 05, 2008, 12:05:25 AM »
Don't know what these CVAR's do QwazyWabbit

1212
tastyspleen.net / Re: Creation of a tastyspleen LoX server?
« on: January 03, 2008, 11:09:53 PM »
Events overtook me this new year. LOX 1.12.14 is available on http://www.windowmeister.com/lox for Linux and Windows. Apologies for the messed up Linux version of the 1.12.13 distro. Accessory to the 1.12.14 release is a model for the improved flashlight. Download http://windowmeister.com/lox/flight.zip and install this model to your models/ folder as ./models/flight/

Version 1.12.13 is stable in Windows but lacks a few tweaks. The Linux .so was defective due to an oversight on my part.

See http://www.clanwos.org/forums/viewtopic.php?p=42220&sid=326be5cfd4cb3ffa58e8d4cafcef6459#42220 for more details.

 :oops:

QW

1213
tastyspleen.net / Re: Creation of a tastyspleen LoX server?
« on: January 03, 2008, 03:11:29 PM »
RailWolf
Hi!
Thanks, it's good to be here.

X7:
Tried copy-pasting the filters, some icons worked, some didn't.
It looks like I don't have some of them or need to define correct paths.

1214
tastyspleen.net / Re: Creation of a tastyspleen LoX server?
« on: January 02, 2008, 07:17:02 PM »
Adding this to ASE's filters.txt file will create a LOX folder under the Quake2 game that catches all the lox servers listed.
I inserted it between AQ2 and RA2 but I don't remember why. In alphabetical order it should have been following the Lithium folder. This seems to catch all the lox servers, even the ones like tastyspleens LOX where they used the uppercase.

Code: [Select]
Quake 2\Action Quake 2
Mutex: Q2GAME
Icon: $BASE\Action\actq2.ico
1 if game ~== "action" keep
2 remove

Quake 2\LOX
Mutex: Q2GAME
1 if game ~== "lox" keep
2 remove

Quake 2\Rocket Arena 2
Mutex: Q2GAME
1 if game ~== "arena" keep
2 remove


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