The TI-99/4A is a home computer from Texas Instruments, successor to the TI-99/4.
The TI-99 computer system consists of
- a console containing the main processing components, a keyboard, video socket, joystick and cassette interface, and a cartridge slot
- peripheral devices attached to the console, either as fully cased devices, or as expansion cards which must be inserted into the Peripheral Expansion Box (P-Box)
- software on cassettes, diskettes, and cartridges
- various human-interface devices (joystick, later also mouse)
This is the mainboard of the TI-99/4A: