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I would like to present you with some more information in email form,
not after adding that it is hard to include all the background
information
that is present on my web pages, and that I've left out non-synthesis
related subjects.
I am an electrical engineer from the University of Delft (Holland),
and have at least 15 year of active electronical and digital design
and implementation knowledge, and about 20 years of the same of
computer experience, hardware and software.
At university I have had a main emphasis on computer graphics, both
during my graduation as during an added 4 years of work in a
computer graphics project where the goal was to implement a specialized
parallel hardware machine, composed of custom and programmable chips,
combined with DSP's and linked with a fast (set of) workstations,
where I focussed on the design as a whole and implemented a working
parallel and distributed simulation of the hardware, prepared a
formal design and simulation environment to efficiently support complex
designs like this, and wrote a lot of graphics and related software.
My experience areas and computer language knowledge include:
- design and implementation of a variety of extremely low budget
synthesizer
and electronical music instrument building blocks, including a fully
home engineered and built mixed analog / digital design synth,
consisting
of a fully polyphonic generator set (top octave synthesizer with
digital
dividers), combined analog mix amplifier/VCA/VCF unit with overdrive,
sine wave lfo for modulating HF generator and VCA/VCF, ADSD
generator,
and a trigger unit/envelope follower fed from the mixing rail,
doubling
as a noise gate trigger. Did this about 15 years ago on a budget of
appr.
$100,- by having a nively shaped wooden cabinet, making my own
contacts
using spring wires and silver ended contect tips, and using as cheap
as
possible parts, because I had to do it on my (mid-highschool)
allowance.
- A analog BBD based delay line with variable rate lf sine modultated
delay time as a choros/lesly unit, later I added a self-designed OTA
bssed compandernouround it
- I built my own design high quality mizer, a powered mixer and several
power amps (up to 2x70W)
- experimented with analog/digital rithms units and made various
working
rythm boxes with them using ttl logic programmable driver modules
- some 20 years ago designed and implemented a shared memory/dma based
multiplexed display and IO unit, based on discrete cmos
components
small static memories, and 16 7 segment LED displays, meant to be
used
with my own 8080 processor card, which was alleviated by my having
access to a trs80 clone.
- based on a 2 MHz Z80 trs80 clone I wrote lots of software, and added
various types of hardware, amoung which da/converters,
- various simple sample recorders, and a variable length software
audio delay line
- sample playboack "dsp" routine for a 2MHz Z80, based on fixed point
variable increment (non-interpolating) looped table lookup
- pitch follower software alternated with sample playback, driven by
my synhesizer extended with an envelope follower and with pulse
lenght measurement hardware
Around the time of starting at university (1984-) and later:
- trs80 based graphical sequencer, (seriously !), with coupled machine
language code to produce duophonic additive synthesis based music
lines
over a 8 bit DA converter sampled at about 8kHz (+ filter),
or drive a home engineered MIDI interface
- midi "out" interface based on discrete ttl components, angineered
from
empirical data (couldn't get the protocol docu, so I borrowed an
oscilliscope and figured the protocol out myself)
- 68000 machine language programs, amount which sample playback
routines
at higher sample rates, also unter midi control
- circuit analysis program using complex matrix solver with
spice-like input parser and graphical output, on an Acorn
electron works very well to
in interaction-time produce graphically represented filter transfer
functions for active but linear moderate complexity circuits.
- Various types of UNIX/C software for a range of applications,
amoung which Atari ST versions for interaction time rendering
of rational Bezier surfaces (3d order doubly curved patches),
and produced a range of UNIX compatible CAD and graphics
design and output programs
- a fast switching, generally useable, non-preemptive multi threading
frame, with very fast socket-type interface inter thread
communication
- a "connection server", which allows for socket based communication
between unrelated processes, dynamically recongfigurable e.g.
recompiling and reconnecting modules in run time,
completely transparent transfer also for distributed links,
no infringement on intrinsic socket speed for local sockets,
very easy to use (only small library for clients, prototype
graphical tool for generating communication C code)
- a decoupled graphical interface with intermediate ascii form
command interface for a chain of programs (CAD, radiosity,
raytracing, harware
rendering simulator image display, and distributed processing
control),
all based on the above communication package
Recently I've prototyped:
- 4 pole (24dB/oct) resonating until oscillation voltage or digitally
controlled analog sampling based filter (25Hz-25kHz range,
but only prototyped with linear voltage control), various
interesting sounding
non-linear extensions...
- 40 MHz Z80 card with high speed low cost multiplying (discrete
component)
da, keyboard interface and afore mentioned display card
- designs for da/ad circuitry suitable for multi channel application
- fast (o(1MHz)) SH/integrator prototypes
- processor (Z80 "breadboard" version, running at up to 40 MHZ!)
linked with: (Acorn "BBC") electron (shared memory), a large piano
type keyboard, midi interface both in software version and in
above hardware version)
- some switched supply , dc-dc converters and analog power amps, and
pwm modulated high power drivers (up to appr. 100W) based on
power MOSFET's.
- made a physical modeling "waveguide" module running (real time for
e.g. 128 nodes) on a 100 MHz Pentium, featuring any number
(tried up to 8k, then sampling noise becomes too prevailent,
no wonder for a 16000 pole filter..) of
2 pole coupled harmonic oscilator modules, with ring feedback or
suspended on both ends with filtered end points,
programmable initial state, and prepare to contain non-linearities
in the transfer and oscillating functions (at the expense of speed).
Experimental, but already producing (32 word width intermediate,
16 bit output) samples.
I've experiene with the following computer languages:
Basic, (UNIX and PC based) C, Objectie C, C++, Pascal, Z80 and 68000
machine
code (assembly), Lisp, Tcl/Tk, Java, Html,
and programming and extensively using the following synthesizer
platforms:
DX7 and TX802, Roland HP3000s piano, REV-7 reverb, RX-15, Bit-one
and DW8000 analog/digital synths, Poly 800, TG500, used and
programmed various samplers and all types of music software
I've written an extensive DX7 patch librarian with graphical interface,
extensive and fast sound search and comparison facilities, MIDI
processing, including graphically editable velocity curve transform,
remote control, and a "uniqifying" library maintenance system. It has
been commercialized and generated appraising professional users.
It has been a long standing desire of mine to work in a US (preferably
Silicon Valey) based environment.
I would like to again point to my internet pages for some additional
info
on:
https://members.tripod.com/~theover/index.html
and will be happy to provide additional information.
Greetings,
Theo Verelst.
(theover@yahoo.com)