From obxwindsurf@yahoo.com Thu Mar 24 23:43:12 2005
Subject:After a year in the making - B4 Realtime Controller is Finished


I know it's been about a year since I last posted about this
project, but I've finally made it through the last round of software
development and I've got a working prototype.

You can see the finished product at:
http://www.vintagemusicprojects.com/B4RTC_images/Assembled.jpg

In the picture you can see Tube Drive and Tube Vol controls - these
are digital knobs with 1 of 8 possible values - originally they were
bank select and program select switches but since I already have
that on the computer keyboard for the B4 and the keyboard's function
keys are very user friendly I decided to not duplicate this on a set
of switches that only gave me 64 presets (8x8).

This unit uses vintage Hammond drawbars (I don't know what year but
I got them off of e-bay for about $25. The most typical functions I
use when I play are available as toggle switches or rotary switches,
including the Hammond Vibrato/Chorus selection. I used a half-moon
for the leslie fast slow control and if you look to the left of the
lower manual drawbars there is a small switch. Since this set of
drawbars only had 8 for the lower manual, the switch couples the 5-
1/3' drawbar to "pull" both the 16 and 5-1/3 or the 16' only
depending on its setting.

This thing uses a custom circuit board utilizing a BasicStamp 2sx
Microcontroller, an 8-line to 3-line priority encoder for the rotary
switch and drawbar data bus, 4-line to 16-line multiplexers for the
drawbar selects (there are channels for pedal drawbars although for
this unit they are not used), and a few gates to map it all into a
contiguous memory map. On the rear panel is a serial I/O port for
programming, a midi out port, and power in from a 9v wall wart.

Now that code is stabilized and running I'll post schematics, more
pictures and source code for those of you who are more adventurous.
Software is copyrighted and if used for commercial development must
be licensed.

This completes my setup: This B4 RTC (real time controller), B4 on
an 850 MHz PIII, Motu Fastlane USB 2x2 midi, Sound Blaster Live 5.1
(use the joystick port for an additional 1x1 Midi channel), Morley
EP-1 expression pedal (out of production since '94), MIDI-OX (for
controller translation from the EP-1 MIDI expression to the B4 Swell
pedal), MIDI-YOKE (to plug the MIDI-OX into an input in the B4),
Yamaha PSR-GX 76 as a self standing sampled keyboard and B4 upper
manual, Kurzweil PC1x as a self standing sampled keyboard and B4
lower manual, and of course my scratch built Leslie 145.