Description RIOT contains 2 8bit ports, timers, IRQ controller and 128bytes of RAM. In Atari consoles it works with joysticks and console switches. Catalogue numbers C010750 C016150 UM6532 Pinout Vss ground Vcc +5V power /RES chip reset Ø2 phase 2 clock input R/W read/write /IRQ interrupt line, activated by PA7 or timer D0-D7 data bus A0-A6 address bus /RS chip RAM select CS1 chip select /CS2 chip select PA0-PA7 bidirectional port A PB0-PB7 bidirectional port B 4 bits of PA are used for first stick, other 4 bits for second stick. 2600: Bits PB0,1,4,6,7 are used for reset, select, b/w, left diff, right diff 7800: Bits PB0,1,3,6,7 are used for reset, select, pause, left diff, right diff 7800: Bits PB2 & 4 are used for output to select 2 button mode. Back (c) 1998-2004 Jindroush Last modified: Tue Dec 3 22:27:52 2002