    ARP 2600
    --------

This synth will probably never get a writeup, it is kind of beyond the scope of
this document. There are some discrepancies with the original:

The filters do not self oscillate, they require an input signal. The output
stage is global to all voices so cannot be patched back into the signal path.
The original did not have a chorus, only a spring reverb. The input stage has
not been tested for either signal nor envelope following code. The voltage
manipulators were not in the first bristol upload with this emulation (-60), 
but a future release will include mixing inverters, a lag processor, and
possibly also a Hz->V extractor. The unit has an extra LFO where the original
had just a clock trigger circuit, it produces a TRI wave, can be used to
trigger the AR envelope and be used for modulation. The electroswitch is
unidirectional, two inputs switchable to one output. The sample and hold 
circuit cannot accept an external clock. The Keyboard inputs to the VCO cannot
accept and alternative signal other than the MIDI note with tracking of this 
note either enabled or disabled.

The rest works, ie, all the VCO/VCF/VCA/ENV/AMP and any of the 30 or so outputs
can be repatched into any of the 50 or so inputs. Patches cause no overhead in
the engine as it uses default buffering when not repatched, so feel free to put
in as many cables as you can fit. Patches in the GUI still demand a lot of CPU
cycles. Release -77 improved this about 5-fold and further improvements are in
the pipeline: the 0.10 stream implemented color caching and XImage graphics
interface which massively improved GUI performance.
