This program demonstrates how to get a 12-bit sample from the Maxim 1270 A/D chip which has 8 channels.
Multiple ADC chips can be connected to the Basic Stamp. Each chip would share a 3-wire connection with the other chips to the Basic Stamp for (1) the Synchronous Clock signal, (2) the Digital Input into the Basic stamp, and (3) the Digital Output from the Basic stamp (which sends commands to the DAC chip). Also, each DAC chip would have its own Chip Select wire connection to the Basic Stamp.
To select a certain chip to transfer data, the Basic Stamp would set the Chip Select of one of the chips to 0 volts, and all of the other Chip Select wires to 5 volts.
Here is a schematic of the circuitry connected to the Basic Stamp IIsx:
