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## January252013

### resonant lowpass gate panel

After getting to build two resonant lowpass gates, a design from old don buchla put into a pcb done by thomas white, i decided to make my own euro front panels for it and share them.

the files are available at github

(c) 1904-2038 wotwot

cc-by-nc-sa

# hercules rmx weight reduction

somewhere i read about the hercules rmx having a piece of steel inside that adds to its total weight. removing it would make it easier to transport to gigs, i thought.

of course, i removed all screws to disassemble the enclosure which resulted in some parts bouncing around, so i really had to go on with my objective.

removing the steel plate was then quite simple. i even managed to reassemble it without having some parts left over. to do it again, it makes sense to only remove some screws and leave at least four of them in place: the only screws on the top side that need to be removed are the six long screws that hold top and bottom case together.

to just remove the piece of steel, it is sufficient to remove the bottom lid only which means removing all screws on the sides and the bottom and the aforementioned six on the left and right side from the top. removing the aluminium cover is trickier but not necessary.

## big is the old old

 even when thought locally. bigger, stronger, louder, and longer might trigger lowlevel patterns but small is as underrated as analog descriptions of great size are overhyped. neither of them is more important than the other. while it might still desirable to maintain an illusion of an overview of reality, rather than thinking of something in always the biggest possible Point of View, it makes sense to look at chaos and remember that all models derived from an approximation of "it/nature/dog/.." are never sufficient to thoroughly describe a more complex system and any focusing on the next big "solution" (hey, you're free to choose your own reality after all) will often lead to a system reacting in a bolder way than necessary. contrary to dawkins, freedom exists, but it often requires almost machine-like precision to go about ones way knowing that exerting your freedom to leave your own path is seldom a good idea. 

to repeat an older meme:

### small is beautiful

interfering into systems to "improve them" is the beginners behaviour that at best resembles the dreams of the wizards apprentice.
 the cake is a lie. the cake factory is a bigger lie. abstractions do not exist. also, closed systems don't either. 

# electronics

some electronics documentation:

edge detectors

# fossil, a dscm

fossil is an open source distributed version control system with some features like

• distributed bug tracking
• distributed wiki
• web interface
• and moar

like a detailed overview cares to explain.

# ardrum

Recently i started making my own drumset. as good e-drums are not quite affordable to me, i set out to build my own with some design goals:

• the individual drums should be sensitive to the place where they get hit
• i wanted the set to be able to play samples as well as to trigger and influence sound synthesis
• it should teach me about arduinos and other microcontrollers
• the sensor input should be processed in an arduino and sent to pure data
• it should be sort of affordable
• standard parts should be used whenever possible

i just came back from work where we checked my 20 yr old piezos with an oscilloscope, they have their first peak between 8.88 and 9ms after being hit. less than 10ms latency should work. among the other drums, these piezos go into the snare, too.

# parts

## electronics

• arduino atmega 168
• plenty of piezos (i still had them and have no idea what kind they are)
• an analog multiplexer to expand the amount of analog arduino inputs

## hid

• 12" snare
• cymbals: plastic crash and ride

## software

• arduino sketch
• pure data patches

# noisefoc

yesterday we built a noisefoc, a little NAND-based square wave synthesizer.

the sounds it makes can be heard in a little video

# putty and ssh public key authentication

hardly ever did i bother to use putty as a normal terminal usually does what i want. unfortunately, there is an "operating system" whose name i will not mention that considers itself so different that the variety of available terminals for it is pretty low.

needing to tunnel an audio stream, i finally engaged in the quest for working ssh public key authentication using putty on such a system. needless to say, i read Chapter 8: Using public keys for SSH authentication and Chapter 9: Using Pageant for authentication of its documentation.

also needless to say, i couldn't have imagined how many pitfalls it contains. on unix, generating a key pair and sending the public key over is something that does not take more than a minute.

putty saved the generated keys somewhere, with the private key named .ppk and the public named whatever. it also offers to export something into openssh format which was what i wanted. i was nevertheless amazed that this file only contains the private key.

the public key that is needed to be put into server:.ssh/authorized_keys looked like some other rsa key that are used for ssl certificates but not very much like the keys that are normally stored in .ssh/authorized_keys. there is something that will output this format that i found on unix but not yet on other platforms,  -O public-openssh.

## remedy:

edit a copy of this public key file with a text editor, delete all the boilerplate stuff, write ssh-rsa / ssh-dsa on the beginning of the line with the actual key, join all further lines of it to just one, append something like user@host at the end and delete all the rest. the file is now ready to be appended to the other keys in authorized_keys.

the documentation on puttygen on unix has options to directly output this format using -O public-openssh . in this case i did it manually, from this:

---- BEGIN SSH2 PUBLIC KEY ----
Comment: "rsa-key-20110410"
AAAAB3NzaC1yc2EAAAABJQAAAIEAqW/3hc9LgrNfYHFdBU37AM45s0OLfDJ1isvh
V5Ug4h0d/YzY8uzjRcZU5FrUz3NAsLlkgZck7M3Dg61/6oSZRDYAOZwsWJWhv+bx
uBY6Y2JEiFTZP1vIJoaj2v3nJz07w5n6ZtueCtodUWLi8MHotC6+zsXEmCbhI1RR
7u/8ork=
---- END SSH2 PUBLIC KEY ----


into this:


ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAIEAqW/3hc9LgrNfYHFdBU37AM45s0OLfDJ1isvhV5Ug4h0d/YzY8uzjRcZU5FrUz3NAsLlkgZck7M3Dg61/6oSZRDYAOZwsWJWhv+bxuBY6Y2JEiFTZP1vIJoaj2v3nJz07w5n6ZtueCtodUWLi8MHotC6+zsXEmCbhI1RR7u/8ork= user@host


## run:

start pageant. i will hang out in the system tray and yes, private keys can be read into it and decrypted at which point it workedforme(tm).

# screwing over a fucked bootloader

## problem:

 u got grub, lilo or something in your partitions but the shit doesnt boot


## solution:

 fuck the harddisks MBR over to get a bootmenu that boots any fuckin partition, regardless of whats inside


## how-to-repeat:

DISCLAIMER: if you wipe your harddisk(s) trying this its your dogdamn own fault.
also, dos partition labels only. no idea if this works on gpt.

NOTE: this snippet was almost finished but got fucked up on the way. it prolly sounded nicer before.

## entering:

some FreeBSD bootmedium (ie. a freesbie image if that works for you or maybe something more recent: a CD, Stick etc)

boot the thing and get root.

make your mind up about which disk you want to replace the MBR of.
if there is just one disk in the box, and this is a PATA disk connected as master on the first bus, the bios will likely call it 0x80 (0x81 for the 2nd etc.).
also, in this case the os will likely call it ad0.

knowing the disks name in terms of bios and OS numbering will help in hitting the right disk.

### making the mbr writable:

  sysctl kern.geom.debugflags=0x10


### write a new mbr without affecting the partitions on it:

  boot0cfg -B -v -d 0x80 ad0


if everything went well, on next reboot you'll be greeted with a little chooser for booting.

## August192010

### hackers, homeopathy and arrogance

Ever wondered why it currently seems so fashionable for hackers to bash on homeopathy ?

well, we got ... numberz ! and to be less boring, put them into some pictures that give a relation.

First of all, lets see for what kinds of people homeopathy actually works and for whom not:

### average effectiveness

strange, heh ?

well, theres moar: as demonstrated, it is easy to understand that people only choose the data that is sufficient to prove their claims. in the current homeopathy bashing, most arguments go on about the theoretical possiblility of any effect based on the amount of thinning of a given substance.

as paracelsus stated that success alone will tell, this gives quite a different picture:

### use only datasets that fit into your mindset

hm... so, really, if someone believes something is completely harmless, then why hit on it ? the winner is quite clear:

### 100%

a clear winner at 100 per cent, not mentioning the small fry companies and users that are hurt by it.

To deviate a bit, an analysis of the hacker mindset in relation to alternative medicine seems in order.

As everyone is a computer expert these days, it should be mentioned that most computer people can maintain an overview over complex matter.
It should however also be mentioned that it mostly only applies to their own field of interest and proficiency and horribly fails at other systems.

### hackers

Does that mean if they cannot maintain a feeling for a complex system outside of their domain it will equally be impossible to still take them seriously ?

It is about time for some lowkicks.

We shall take a look at their self image and how it deviates from reality.

Taking into account that they have access to a lot of information on the interwebs, this might suggest an onmisciencent belief system coupled with some more illusions:

### omniscient beliefs

reality shows a different picture, one of delusion.

This leads us to the difference between life and its skewed image in the mirror of the web:

### delusions

For people who are strictly to adhere to the dogma of duality expressed in ones and zeroes, anything fuzzy is an unlikely encounter:

### a straight mindset

But what the heck anyway, would you rather get an operation by a computer-illiterate surgeon or a hacker believing he/she knows about medicine ? How often have hackers helped you medically ?

What if conventional medicine fails ? If alternative medicine were totally non-effective, how could it hurt trying an alternative ?

fact is that there is a significant amount of so-called hopeless cases that were solved by "ineffective and unscientific" means.

### doh.

To be able to spot a hunch of an explanation, we need to leave the rational battlefield and enter martial arts. This view allows us to pinpoint a fundamental difference between hackers and medics from any field.

### The Difference

This clearly gives an indication that a certain energy level needed to administer and receive alternative medical treatment is lacking at our aforementioned subjects.

Life is not a game where Experience Points can be gained by sitting in front of a screen and clicking at the things that pass by.

On the contrary, using computers for several times a day leads to a deprivation in energy that cannot adequately be quenched by pizza:

### computers suck

To increase the amount of MediPacks (ie. Health), it makes sense to turn the box off once in a while and stop bitching about stuff one does not have a clue about.

Hugh.

# audiosetup

this is a collection of information i went through to set up a digital audio workstation (DAW) running on linux.

as far as the systems here were concerned, the distros used for the setup were debian squeeze (testing), ubuntu intrepid, karmic and lucid, for other distros take a look at http://wiki.linuxmusicians.com/doku.php?id=linux_multimedia_distro_s.

## 3. putting it all together

data rates, bit depth, midi, osc

## theory

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