EDRUPT - My Speakers

The story of EDRUPT is an esoteric mystery of NASA’s Apollo moon missions.  Did you know that the Apollo Guidance Computer (AGC) was the first computer built with integrated circuits a.k.a. chips?  Containing 4,100 chips strung together by hand with wire wrap and solidified inside clear epoxy, the AGC was used in all of NASA’s manned moon missions.  Details of its operation have been disclosed, but one of the computer’s designers included a strange and poorly documented machine instruction called EDRUPT.  It was used only once in the mission, during the phase when the Lunar Module made its descent toward the moon’s surface under digital control.  Retro computing enthusiasts can simulate the AGC’s Luminary 131 software on desktop machines but its found that the system breaks unless EDRUPT is removed from the code.  One understanding of EDRUPT is that it instructed the computer to send data to an unknown destination elsewhere in the spacecraft.  But why is EDRUPT a missing piece of the puzzle?  What was contained in the data it sent?  And… what or who was the intended recipient?

 e-squared on kvrx

I wrote a retro technology holiday gift guide for Make:Online.  It appeared on Nov 30.  Ironically, I haven’t given holiday gifts a.k.a. christmazz prezntz to anybody for years :0

I’ve posted new useful info for Seeburg (Gulbransen) Select-a-Rhythm drum machine owners.   The full 70-page service manual is available as a PDF download here, including schematics and a technical description of everything inside.  Thanks to Ramiro Jeancarlo for sending a photocopied version of the manual, and thanks to Lace D for scanning it.

Andromeda Mk-1 and Mk-2 kits are shipping.  The first batch of kits is almost sold out but I am revising the designs and will re-order boards soon.  Andromeda Mk-3 and Mk-4 kits will be out soon.  Mk-3 is a twangy synth sound, and Mk-4 is a tuneable boomin bass drum.

live set (34:40) 11-14-2009

12 x ASR mini analog drum machines

In other related news, Nathan Wooster designed a PCB for his MIDI-to-IR sync converter, which lets a computer or MIDI sequencer be the master clock for all of these things.

The 4MS Autonomous Bassline Generator is now available as a kit from 4ms Pedals.  We’ll be teaching 20 people how to build them at the Handmade Music Austin workshop #2 on Nov. 15th.

In December, we’ll introduce the Nebulophone synth kit from Bleep Labs.

electronic music from Eric Archer on Vimeo.

thanks to iloveanalogue.blogspot.com for this video interview!

Thanks to everybody who came out to Cherrywood to hear my set last night.  It was cool meeting new DIY/electro people and seeing old friends.  The set didnt get recorded, but here’s a track pieced together from rehearsal tapes.

rehearsal oct 2009

I like to build something new for every gig.  This show I added a 10×10 drum trigger routing matrix.  I found this killer switch matrix at the Black Hole of Los Alamos (r.i.p. Ed Grothus).  That means it was probably originally purchased by Los Alamos National Labs for nuclear weapons research… death rock indeed.

Here’s whats coming up…

THURSDAY OCT 15: Dorkbot 21 @ Cafe Mundi

Arthropod Space Wreckers live demo!!

Location: Cafe Mundi 1704 E 5th St.
Thurs. Oct 15th 2009
7:30-9:00pm

SUNDAY OCT 18: Handmade Music Austin workshop #1

I’m teaching class on how to build your own Andromeda Space Rockers mini-drum machine.  Expert instructors from Bleep Labs and 4ms Pedals will be there too.  Registration is closed for October but there are six more monthly workshops planned so you can still get in.  And the performances (8:30 - ?) are free to attend so c’mon down.

Salvage Vanguard Theater
2803 Manor Rd
Austin, TX

4PM - 5:30 beginner’s workshop
6PM – 8 instrument building class
8:30 – ? DIY music performance

A performance by featured artists Static Storm System will close out the event.

I’m testing the definition of “drum machine” with these fun little prototypes. They have only two chips, (TL06x opamp and CD4089). No microcontroller. One knob (tempo). One button (reset). Sixteen rhythm presets on a DIP switch. Light reactive circuits to bend the sound.

Even though the machines can play alone, they’d rather play in a group. Thats because each machine has an infrared transmitter and receiver. This lets them form a wireless network to play at the same tempo. The IR link is limited to about 12″ and does not work under bright incandescent light. (the video was shot with compact fluorescent)

At the end of the video I show how interrupting the IR link affects the sound. In theory, many of these machines could be networked.

Both machines in the video share the same sequencer design. It is based on the CD4089 binary rate multiplier. Their sounds are different though. The unit in the foreground uses a pair of bridged-T oscillators to make clave / rimshot / bongo sounds. The unit in the back generates filtered noise bursts with a classic “swing VCA” mechanism.

Once finalized the designs are intended for use in a fun educational workshop setting.

Stay tuned.

- eric

EA at Salvage Vanguard Theatre 8.2.09

bonus rehearsal recordings:

 through the wires

microcosmicmachinedream

Yes, the tongue is mounted backwards in one of the photos.

Here’s a recording of my maniacal and amateurish daxophone stylings.  The accompaniment is electronic percussion from a pair of analog percussion circuits I’m designing, based on TR808 sounds with ‘extraterrestrial’ modifications.

 extraterrestrializer vs daxophone

Here are some daily demo recordings of improv playing, with everything connected.  Just getting a feel for mixing… trying different styles… thinking about what to build next.

LFG shreddin’:  feb 13 09

bouncy ball hihats:  feb 15 09

bedtime music:  feb 16 09

EA luvz gabber:  feb 17 09

nod yr hedz:  feb 18 09

 robot send love: feb 20 09