Memory Expansion - NCR PC4I Technical Reference

SYSTEM OVERVIEW
MEMORY EXPABSIOH
The NCR PERSONAL COMPUTER is supplied with 256 KB
random access memory on the main processor board. To
upgrade memory capacity, two additional kits are
available:
* K101
A memory expansion board with 64 KB of memory,
starting at machine location 40000H. In
addition, this kit contains sockets for 5 banks
each of
9
integrated circuits, so that memory
can be further expanded using up to 5 kits K100.
*
K100
A set of integrated circuits for insertion on
the memory expansion board K101. K100 upgrades
the system memory capacity by 64 KB.
Installing the maximum 5 kits K100 creates a
total system memory capacity of 640 KB, that is
up to, but not including, the machine location (
OAOOOOH. (Address area from this location
upwards is reserved for video display memory and
the NCR PERSONAL COMPUTER ROM BIOS.)
Memory banks should be populated in ascending address
sequence. Configuration switches on the memor·y
expansion board must be set to reflect the amount of
expansion memory (see Figure 1.10).
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Figure 1.9 Memory Expansion Board (K101)
1-18
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