Appendix DSpecificationsCPU and Memory32-bit CPUSystem speedSystem memoryROMShadow RAMMath coprocessorClock/calendarCache controller25 MHz system: 80486SX processor,50 MHz system: 80486DX2/50 processor25 MHz regardless of CPU; for 80486DX2/50,50 MHz speed is internal only; 8 MHzspeed is simulated by inserting wait states;high/low speed selection throughsoftware or keyboard command; 0 waitstate memory access at high speed4MB RAM standard soldered onto thememory card; base memory of either256KB, 512KB, or 640KB, selectablethrough jumpers; memory expandableusing 256KB or 1MB SIMMs up to 16MB(maximum); SIMMs must be 80ns (orfaster) access speed128KB (includes system and VGA BIOS)0 wait state access speed; automaticallycopies both ROM BIOS and video ROMinto RAMStandard for 50 MHz model; on 25 MHzmodel, 80486SX microprocessor can bereplaced with optional 80487SX chipReal-time clock, calendar, and 50-byteCMOS RAM; battery backup82385 (25 MHz) standardSpecifications D-1
