Control Register (2D4) - IBM 3278 Technical Reference

Control Register (2D4)
This is an 8-bit Read/Write register internal to the emulation
adapter and accessed by the IBM Personal Computer.
It
requires
one address to read and write.
Bit
Function
0
Coax Enable
1
Reserved
2
Reserved
3
Keystroke Available
4
Reserved
5
Test
6
Reserved
7
Disable Interrupt
Control Register
1-7