Octek HIPPO II 486, Manual

Page: 32 / 107

CONFIGURING THE SYSTEM
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CONFIGURATION OF MEMORY
The configuration of the memory is very flexible.
There are several combinations of DRAM types you may
consider. 256KB, 1MB or 4MB SIMM are acceptable. So,
a basic system can be equipped with fewer memory and
later more memory can be installed when upgrading the
system. There are two banks of DRAM on the
motherboard and another two banks on a memory
expansion board. The memory size is detected
automatically by system BIOS and indicated during
memory test after reset. No jumper is needed to be set
for the memory size and DRAM type.
70ns DRAM is required. To determine what DRAM
speed rating should be used depends on the system
speed and wait state. The highest performance is
accomplished by using zero wait state, but high speed
DRAM has to be used. If zero wait state is selected, fast
page mode DRAM is needed. The wait state setting is
applied to all banks of memory. Therefore make sure to
install DRAM with the same speed rating, or
accommodate the wait state setting to the slow DRAM
type.
Because of the shadow RAM function, the 386KB
memory between 640KB to 1MB can not accessed. So,
the memory size found by the system BIOS is not equal
to the actual memory size. For example, when there is
4MB on board, the BIOS will show 3712KB.