Cursor Address Register (2D2, 2D3) - IBM 3278 Technical Reference

Cursor Address Register (2D2, 2D3)
This 16-bit register is internal to and is set by the emulation
adapter. This register requires two addresses and can be read by
the IBM Personal Computer. This register contains the current
value of the I/O Address Counter. In 3278/79 emulation mode,
this register indicates the location of the cursor.
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