[sdiy] Substitute for pin matrixes?

[Magnus Danielson]

Derek Holzer wrote:
> In this vein, can anyone tell me how the program cards for the Buchla 
> Music Easel work?
> 
> FROM http://www.buchla.com/historical/music_easel/music_easel.html
> 
>> Further augmenting the Music Easel's real time performability is the 
>> capability of permanently storing and immediately retrieving complete 
>> instrument definitions (patches) or portions thereof. (An "instrument 
>> definition" includes settings of parameters, degrees of articulation, 
>> switch positions and interconnections.) Storage entails the 
>> installment of resistors on program cards; retrieval is accomplished 
>> by plugging in a desired program card and activating a switch.
> 
> FROM http://www.vintagesynth.com/misc/buchla200.php
> 
>> The Music Easel also featured a relative breakthrough for its time: 
>> Patch storage! But it was rudimentary storage - resistors installed to 
>> "program" cards were used. You needed one card full of resistors for 
>> each patch and they had to be manually plugged in to be used. They 
>> stored slider, switch and knob positions as well as patch-point 
>> connections. To be used they had to be inserted into a slot, one at a 
>> time, on the upper left side of the synth. They can also be seen in 
>> the picture above in their own storage compartment directly above the 
>> patch cord storage compartment. The Music Easel originally sold with 
>> six blank cards and some resistors and instructions.
> 
> Is it also like a matrix with pre-patched connections on each card? 
> Various voltage-dividing resistors?

Just sit and look at this picture and it will come to you:
http://rubidium.dyndns.org/~magnus/synths/companies/buchla/Buchla_2081_prog_300.jpg

More Buchla-stuff at:
http://rubidium.dyndns.org/~magnus/synths/companies/buchla/

This is more of a pre-patch just like the EMS pre-patch boards of the 
same vintage. It doesn't replace the patch-matrix as an interactive 
interface, but it replaces or complements the patch-matrix for basic 
setup. The point is that onces you have setup things like you want, you 
can migrate them over to the patch-board. Swapping patch-boards should 
significantly reduce the time to switch sound.

You can't play the matrix with a presto-patch board, so you still want 
the matrix for that.

You want resistance between the X and Y lines, so most of the switch 
chips doesn't really work well.

The Sealectron patch matrixes wasn't THAT advanced in their design. Well 
kept they are nice to work with.

Cheers,
Magnus