UMBPCI is an UMB (Upper Memory Block) driver (MS HIMEM.SYS extender) for Intel, ALI, VIA and SiS PCI/AGP chipsets.

UMBPCI is a replacement for EMM386. It extends the HIMEM.SYS of DOS or Windows 95 by the function 'Request XMS UMB' (These are the 240 Bytes which stay in memory).

UMBPCI makes UMBs from disabled memory that is intended as Shadow-RAM. UMBPCI enables this memory and disables its write protection. It needs only 240 bytes of low memory,