Inside the Apple III

The Hardware (Cont’d)

Similarly to the Apple II and Apple II Plus, the Apple III used mostly “regular” TTL integrated circuits that you could buy at any electronic components store. The biggest integrated circuits, besides the 6502 microprocessor, were two 6522 “Versatile Interface Adapters” for I/O communications and one custom keyboard controller called 341-0035. The empty socket located on position “B3” of the motherboard was reserved for the 58167 clock/calendar integrated circuit, which was now optional, as previously mentioned. Other “big” chips used on the Apple III motherboard included the 6551 serial controller, a custom video mode selector called 341-0032 (which was actually a ROM chip), and a custom video elements/attributes generator called 341-0030 or 2316. 

Figure 9: The main integrated circuits

Figure 10: The keyboard controller