The Tektronix TDS784D is a Digital Phosphor Oscilloscope. This model has 29 automatic measurements and measurement statistics and a record length of 50K points (which can be extended with options).
The TDS794D is a Digital Phosphor Oscilloscope manufactured by Tektronix. The TDS794D has a maximum sample rate of 4 GS/s and a record length of 50K for every channel (Option 1M: 130 K; Option 2M: 2M).