Vdd - Voltage Drain Drain
Vee - Voltage Emitter Emitter
Vss - Voltage Source Source
Vcc -- For TTL circuitry, this is the +5 volts which sits on the collector of the bi-polar transistor output circuit.
Vee -- For TTL circuitry, this is the GND which sits on the emitter of a bi-polar transistor output circuit.
Vdd -- For CMOS circuitry (like the PIC) this is the +5 (or +3) voltage that sits on the 'drain' of a
MOS-FET transistor output circuit.
Vss -- For CMOS circuitry, this is the GND that sits on the 'source' of a MOS-FET transistor output circuit.
Vee - Voltage Emitter Emitter
Vss - Voltage Source Source
Vcc -- For TTL circuitry, this is the +5 volts which sits on the collector of the bi-polar transistor output circuit.
Vee -- For TTL circuitry, this is the GND which sits on the emitter of a bi-polar transistor output circuit.
Vdd -- For CMOS circuitry (like the PIC) this is the +5 (or +3) voltage that sits on the 'drain' of a
MOS-FET transistor output circuit.
Vss -- For CMOS circuitry, this is the GND that sits on the 'source' of a MOS-FET transistor output circuit.