Program code 0160 using a CABLE device button. On Radio Shack remotes the 'A' button is mapped to CHANNEL UP and the 'B' button is mapped to CHANNEL DOWN, but on the Cinema 7 you will have to program the advanced codes:

181 - 'A'
213 - 'B'

I would recommend that you "key move" these two buttons over to some unused buttons under the TV or VCR device keys, so you don't have to waste a device key on the A/B switch. If you don't have PIP on your TV, maybe you could use the SWAP and MOVE buttons.