Interrupt/Status Register (2Do) - IBM 3278 Technical Reference

Interrupt/Status Register (2DO)
This 8-bit register on the emulation adapter is accessed by the
IBM Personal Computer. Bits 0 through 5 are Interrupt
(I)
bits,
which are set by the emulation adapter and reset by the IBM
Personal Computer. Bits 6 and 7 are Status (S) bits, which are set
and reset by the adapter.
Note: Interrupt Level-2 is used by the emulation adapter.
Bit I/S
Function
0
I Keystro ke Accepted
1 I
Reset Command Decoded
2 I Visual/Sound Register Updated
3
I Reserved
4 I
Base Buffer Modified Complete
5 I
Load I/O Address Command Decoded
6 S
Buffer Being Modified
7
S
Interrupt Generated
Interrupt/Status Register
1-4