As with every other component, motherboards have come a long way from the original IBM PC of 1981. If you're old enough to remember the first De Lorean DMC-12, perhaps the original PC XT mobo still casts some dark shadow over your memory? At the time there were certainly wonders to behold; these days, they simply look a mess with integration the last thing on the designers mind and all the IO having to be decidedly off-board.
The XT had all the same parts as today's mobos, they just worked a little slower. Instead of having a dedicated, integrated chipset, the XT used discrete off-the-shelf components: clock generators, DMA controller, interrupt handler, keyboard and bus controllers, a system timer and a real-time clock, along with the CPU, FPU, ROM and system memory.