Memory Assignment - Control Data Corporation INFORMATION SYSTEMS TERMINAL II Hardware Maintenance Manual

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RAM
8000.&
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7FFF'
6
..
RAM
0800.&
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0 7 F F . & - - - - ..
~ ~
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Figure 4-17. Memory Assignment
DISPLAY
REFRESH
MEMORY
PROGRAM
MEMORY
03357
Read-Only Memory - There are 2K by 8 words of ROM in the
~erminal.
Starting address is 0000 16 and final address
1S 07FF 16 • Access time of this memory is 350 nanoseconds.
Program RAM - The terminal has a m1n1mum of 16K 8-bit words
of RAM. A memory expansion can be added to obtain a total
of 32K 8-bit words of RAM.
Starting address for the basic program memory is 0000 1 6
and final address is 3FFF16. The first address of the
memory expansion is 400016 and the final address is
7FFF 16 • Access time is 300 nanoseconds.
82100083
NOTE
The set of addresses between 0000 1 6
and 07FF16 define both ROM and
RAM. Upon power on or activation of
the RESET switch, this range of
addresses selects the ROM, and
remains in this mode until the pro-
gram instructs the hardware to
deselect the ROM and select the
RAM
(or vice versa).
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