386 motherboard using the CS8230 chipset © 198? Unknown
Released in the late 1980s, the CS8230 AT/386 CHIPSet was designed to provide a "100% IBM PC AT compatible" architecture for the 80386 processor. While your previously documented OPTi and ALi boards represent the transition to hybrid/PCI architectures, the CS8230 represents the "Golden Age of ISA-based 386 systems," where stability and compatibility were the primary design goals.
Implementation: A seven-chip VLSI (Very Large Scale Integration) set, which included the 82C301 Bus Controller and 82C302 Page/Interleave Memory Controller.
Processor Support: Designed specifically for the Intel 80386DX at 16, 20, or 25 MHz.
Memory Architecture: Supported up to 16MB of DRAM with a "Page/Interleave" memory subsystem, which was a significant performance innovation at the time.
Bus Interface: Strictly ISA (AT bus). It was designed before the standardization of VESA Local Bus (VLB).
Peripherals: Often paired with the C&T 82C206 Integrated Peripherals Controller (IPC), which replaced several discrete chips (timers, interrupt controllers, DMA controllers) that were previously spread across the motherboard.
"40 ICs plus memory": C&T famously marketed this chipset by stating that a complete 386 motherboard could be built using only 40 components plus memory. This was a massive cost-saver for manufacturers, helping the 386 drop in price and become the standard for office PCs by 1990–1991.
BIOS ROMs (HI/LO): Boards using the CS8230 almost exclusively utilized a "HI/LO" BIOS pair (two physical EPROM chips for the system BIOS). If you encounter one, remember that you need to read both chips and combine them into a single binary image to successfully dump the BIOS for preservation.
Jumpers and Wait-States: This chipset was famous for allowing "Programmable Wait States." In the BIOS, you could tighten the memory timings to gain performance, but doing so often made the system unstable—a "fine-tuning" ritual that many early PC enthusiasts remember fondly.