This is no data transfer routine if i remember correctly, this is direct access to the hardware, so you have to write your own data sending routines if you want to send actual numbers. Here is my understanding of the command:
The IO cable has 3 wires, called the tip, ring, and ground. Ground is not used for transfering data, so we will only concern ourselves with the tip and the ring. The ring and the tip can either be in two 'states' or voltages, high and low. The calculator can either "pull" a ring/tip low, or let it go high. What this means is that if it is "pulled" low, the calculator forces the tip/ring to go into a low voltage. Even if the other calculator is letting the voltage go high, the tip/ring will still be at low. Thats where the term "pulling low" comes from, because the calculator "pulls" and forces the voltage. When the calculator "lets the voltage go high" it does not force it, but only lets it go. If both calculators let go, the voltage goes high. If either one (or both) of the calculators is pulling low, the line will be read as low.
To SET the cable, use the #->Port command.
0 lets both lines go high
1 pulls the tip low
2 pulls the ring low
3 pulls both lines low
To READ the port, use the Port->Var command.
0 means both lines are low
1 means tip is high
2 means ring is high
3 means both lines are high
Yeah reading and writing is confuzzling, but thats the way it works unfortunately. Note that i haven't actually used the link port at all so all of this is conceptual
if any of this is incorrect please let me know!
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I hope you finish your entry graphmastur! And everybody else too ^^
