Math functions 
Add  Out(0) = In(0) + In(1); 
Subtract  Out(0) = In(0)  In(1); 
Multiply  Out(0) = In(0) * In(1); 
Divide  if (In(1)) Out(0) = In(0) / In(1);
If In(1) == 0.0 the output will not be updated 
Absolute  Out(0) = (In(0) > 0.0 ? In(0) : In(0)); 
DivMod  if (In(1) != 0.0)
{
Out(0) = ((int)In(0)/(int)In(1));
Out(1) = ((int)In(0)%(int)In(1));
}
If In(1) == 0.0 the output will not be updated )
Provides integer operation but all inputs and outputs are floats

IntFract  Out(0) = (int)In(0);
Out(1) = In(0)  Out(0); 
CeilFloor  Out(0) = ceil(In(0));
Out(1) = floor(In(0)); 
ExpLog  Out(0) = exp(In(0));
Out(1) = log(In(0)); 
Power  Out(0) = pow(In(0), In(1)); 
Trig & Calc functions 
Sin  Out(0) = sin (In(0)); 
Cos  Out(0) = cos (In(0)); 
Integral  Out(0) = Out(0)+In(0)*In(1);
Simple scaled integral
In(2) provides update step interval 
Difference  Out(0) = Out(0)+(In(1)*(In(0)Out(0)));
Simple scaled difference
In(2) provides update step interval 
Comparison functions 
Compare  Out(0) = In(0) >= In(1) ? 1.0 : 0.0; 
MinMax  Out(0) = In(0) >= In(1) ? In(0) : In(1);
Out(1) = In(0) >= In(1) ? In(1) : In(0); 
Hysteresis  Out(0) = fabs(In(0)) >= fabs(In (1)) ? In(0) : 0.0;
Out(0) is zero if In(0) is less than the magnitude of In(1)
Out(0) follows In(0) whilst it is >= the magnitude of In(1) 
Logic functions 
(as usual 0.0 => false, any non zero => false, true output => 1.0) 
And  Out(0) = In(0) && In(1); 
Or  Out(0) = In(0)  In(1); 
Xor  Out(0) = (In(0)  In(1)) && !(In(0) && In(1)); 
Not  Out(0) = !In(0); 
Bistable  if (In(0)) Out(0) = Out(0) ? 0.0 : 1.0; 
RSFlipFlop  if (In(1)) Out(0) = In(0) ? 0.0 : 1.0; 
Utility functions 
Constant  Out(0) = user entered constant 
Delay  Out(0) = Out(1); Out(1) = In(0);
(uses Out(1) to store the previous value) 
Filter  Implements a simple digital filter.
In(0)  signal in, In(1)  sample control, Out(0)  filtered output
The sample rate sets the frequency response
Low pass and high pass frequncy = 1/8 of the sample rate
Band pass allows frequnciesbetween 1/2 and 1/4 of the sample rate

Counter  if (In(0)) Out(0) = In(1) ? Out(0) + 1.0 : Out(0)  1.0;
if (!In(2)) Out(0) = 0.0;
Implements an up/down counter
In(0) pulse input  must toggle zero/nonzero
In(1) direction  0.0 => down, nonzero => up
In(2) will rest the counter (when nonzero) 
Timer  Implements a (seconds) timer
Out(0) is the elapsed time from reset
In(0) will rest the timer (when nonzero)
The user can set the rate at which the output is updated 
Ticker  Variable frequency square wave (0.0, 1.0) output
The user sets the period (1/2 * frequency)
In(0) will rest the ticker (when nonzero) 
TrackHold  if (In(1)) Out(0) = In(0);
While In(0) is nonzero Out(0) follows In(0)
When In(0) goes to zero the last output value is held 
EdgeSample  if (In(1) && !Out(1)) Out(0) = In(0);
Out(1) = In(1) ? 1.0 : 0.0;
In(0) is instantaneously sampled when In(1) goes from zero
Out(0) remains fixed until the next sample (rising edge of In(1)
Out(1) hold last state of In(1) 
IO functions 
Get  Creates a user input entry box at the bottom of the window 
Print  Creates a box which displays its input 
Graph  Creates a child window displaying an xy graph
In(0) has the y value, In(1) has the x value
The graph has 1 < x < +1, and 1 < y < +1
The scale and offset can be set to create values in this range
ie 1 < ((input * scale) + offset) < +1
The graph is only updated on a change of x  In(1) 
Chart  Creates a child window displaying an yt chart
In(0) has the y value, In(1) steps the chart forward
The graph has 1 < y < +1
The scale and offset can be set to create values in this range
ie 1 < ((input * scale) + offset) < +1
The graph is updated on a change of In(1) from zero to nonzero 
IO functions 
Module  Creates a module  a function made up of other functions
The user specifies the numbers of inputs and outputs
Right click the top left corner hot spot to descend into a module
 or ascend from one. 
Perl  Povides an interface to an external Perl script
The deltaFSD function will then execute a Perl sub in the script
The first invocation requires the script file
Then user specifies the sub name and the numbers of inputs and outputs
See the notes in the samples section for more information 
Socket  Creates a bidirectional socket (stream) interface
Data is transferred as comma separated channel,value pairs
The default port number is 6739
The user specifies the numbers of inputs and outputs
deltaFSD acts as a server so clients can connect from anywhere  "localhost" or via network
See the notes in the samples section for more information 