It generally only included the northbridge and southbridge.

I'm not really a hardware person, but I always thought "chipset" meant the on-board non-CPU chips that don't drive external hardware, but are nonetheless an essential part of the PC architecture expected to be present by all OS's, like the 8253 timer [1], the PIC [2], or the DMA controller [3].

By contrast, I'd say hardware like the 16550 UART [4] isn't part of the chipset, rather it's part of the serial port which it drives.

> northbridge and southbridge controller

Yeah, memory and I/O control is part of the chipset too, since a CPU without I/O or memory is just an expensive paperweight (or, if powered, an expensive heater).

> HDD controllers, audio and network integrated circuits.

I'd consider these to be more like devices or device drivers.

> bios and cmos

This is kind of a special case. If you ask a CPU guy, it's not a part of the chipset, they're just memory modules with different properties from normal RAM. If you ask a motherboard guy, it is part of the chipset. It depends on who you ask.

I can't really cite these distinctions anywhere, it's more along the lines of the intuitions I've picked up from spending decades around computers.

[1] http://en.wikipedia.org/wiki/Intel_8253

[2] http://en.wikipedia.org/wiki/Programmable_Interrupt_Controll...

[3] http://en.wikipedia.org/wiki/Direct_memory_access

[4] http://en.wikipedia.org/wiki/16550

Remember the original IBM PC and PC AT motherboards that used discrete chips like the 8259 and 8254?