MEM A000h:8504h - S3 ViRGE - MEMORY-MAPPED SUBSYSTEM REGISTERS Size: 12 BYTEs Note: the S3 graphics processor registers can be mapped at either linear 000A0000h or at offset 16M from the start of the linear frame buffer Format of S3 memory-mapped subsystem registers: Offset Size Description (Table M0071) 8504h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. subsystem Control/Status Register (see PORTIBM PC Portable (uses same BIOS as XT) 42E8h,PORTIBM PC Portable (uses same BIOS as XT) 9AE8h) on read: bit 13 indicates whether graphics processor is busy bits 12-8 indicate number of free FIFO slots 8508h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. ??? 850Ch DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. advanced function control (see PORTIBM PC Portable (uses same BIOS as XT) 4AE8h) SeeAlso: #M0073,#M0057,#M0072