This is an original owner's manual for the Texas Instruments Peripheral Expansion System, Model No. PHP1200. Published in 1982, this manual provides detailed instructions and information for setting up, operating, and troubleshooting the expansion system for Texas Instruments Home Computers. It includes important details like FCC compliance and an addendum regarding the ON/OFF switch and fuse holder. This is a valuable resource for collectors, enthusiasts, or anyone still using or restoring vintage TI computer equipment.