Description:

UM82C390 40MHz 386 PC Chip Set

Not much is known about this chip combination, other than it exists. The 482 part is an Integrated System Controller. Some motherboards swap the 391 part for the 481 part. This is known as the UMC UM82C480 (386/486 PC Chip Set) for which we have datasheets. The 481 part is called an Integrated Memory Controller, so it follows that the 391 part is also a memory controller.

The only real source of information on this chipset is from The Last Byte Memory Manager documentation. Here it lists the 391 as being the UM82C390 40MHz chipset.

Documented parts

• (any brand) 82C206 (DMA, IRQ, timer and RTC ctrl.) (known as: PCChips H82C206L , Chips & Technologies P82C206 , Samsung KS83C206Q , UMC UM82C206F , SiS 85C206 , OPTi F82C206Q )
• UMC UM82C482