Intel s Early 386486 Chipsets

Intel's Early 386/486 Chipsets

Intel's first real PC motherboard chipset was the 82350 chipset for the 386DX and 486 processors. This chipset was not very successful, mainly because the EISA bus was not very popular and many other manufacturers were making standard 386 and 486 motherboard chipsets at the time. The market changed very quickly, and Intel dropped the EISA bus support and introduced follow-up 486 chipsets that were much more successful.

Table 4.13 shows the Intel 486 chipsets.

Table 4.13. Intel 486 Motherboard Chipsets

Chipset	420TX	420EX	420ZX
Code name	Saturn	Aries	Saturn II
Date introduced	Nov. 1992	March 1994	March 1994
Processor	5V 486	5V/3.3V 486	5V/3.3V 486
Bus speed	Up to 33MHz	Up to 50MHz	Up to 33MHz
SMP (dual CPUs)	No	No	No
Memory types	FPM	FPM	FPM
Parity/ECC	Parity	Parity	Parity
Max. memory	128MB	128MB	160MB
L2 cache type	Async	Async	Async
PCI support	2.0	2.0	2.1
AGP support	No	No	No
AGP = Accelerated graphics port
FPM = Fast page mode
PCI = Peripheral component interconnect
SMP = Symmetric multiprocessing (dual processors)
Note: PCI 2.1 supports concurrent PCI operations.

The 420 series chipsets were the first to introduce the North/South Bridge design that is still used in many chipsets today.