Asynchronous counters are a type of logic counter that uses a single external clock, that is wired in series to the next flip flop, and so on and so forth. Because of this, there is a signal delay that causes a slight "ripple effect" when some numbers change. A synchronous counter is triggered by the same clock simultaneously so there is no signal delay, thus no ripple effect. The 74LS163 chip has some interesting characteristics. One thing that mainly sets it apart is that it is only an up counter. This chip also shows what you wire it ti detect. The other chip, 74LS193, can be used as an up or down counter; it just depends on how you wire the clock. The construction of this circuit wasn't too hard of a challenge, but it definitely tested our skills on multisim, and our knowledge of synchronous counters. When building the ones circuit, i used the the 74LS163 chip for my tens and the flip flops (74LS176) for my ones. I wired my ones/ flip flops to load a zero and detect a ten so it would only show nine. This acted somewhat like a clock signal for the tens so that when the ones were about to hit ten, the tens will move up a number. I wired my tens using 74LS163 and made the 0-5 range by connecting the inputs to ground and making it detect a 5 because this chip shows what you make it detect. Switches were also wired in using AND gates to act as pause and reset switches so we could pause the count, and reset it at any given time. I don't recall anybodies circuit being incredibly different than mine. One small thing i noticed was the type of display used. i used a seven segment common cathode, other students used common anode, and some just used LEDs.