VINE’s processor uses balanced ternary (‘Bal3’). In balanced ternary, we have three digits with which to write numbers: + (1), o (0), and - (-1). These symbols are specific to VINE; they have been chosen so they are not confused with decimal numbers (hence the ‘o’ rather than ‘0’).
⚠️ Note: different places may use different symbols to refer to the same concept, or the same names to refer to different things. For example, Wikipedia uses 1, 0, and T, instead of VINE’s +, o, and -, to refer to the same values.
Balanced ternary is very useful when compared with more standard number systems such as binary or decimal as it allows us to have the sign of a number be part of its normal representation. To illustrate this, consider the decimal number -3. We have to represent this using a minus sign to show that it is negative. With balanced ternary, we can simply write it as -o (vs +o for 3). This means that there is only one possible representation for zero and there is no need to separate processor instructions for ‘signed’ or ‘unsigned’ integers.
A trit is a single ternary digit and a tryte is a sequence of exactly nine trits. This means that a single tryte may store values in the range ++++++++ (9841) to ——— (-9841), which is 19683 unique values.