Allen-Bradley 1784-KTX Reference Manual page 18

Chapter 2
Start up and Shutdown
2-2
KTx Status Register (byte :0804h)
Important: This is a read-only byte.
This byte reports the status of several properties of the KTx card.
This table describes what each bit contains.
Bit Status Code Meaning
7 0 = Z80 is de asserted
1 = Z80 is asserted
6 0 = Z80 is in the halt state
1 = Z80 is not in the halt state
5 0
4 0
3 0
2 0
1 0
0 0 = no hardware interrupt is currently asserted
1 = a hardware interrupt is currently asserted
(stays active till host writes 0x1 to 808)
Host Interrupt Acknowledge (byte :0808h)
Write a 01h to this address to acknowledge an interrupt from the KTx.
This will reset bit 0 of the status register.
Card Control Write Register (byte :080Ah)
Important: This is a write-only register.
Bit Status Code Meaning
7 unused
6
5
4
3
2
1 1 = puts the KTx into E/ISA 16 bit mode; will not work
with 8 bit devices in the same 128K block of memory
0 = extended 16 bit mode; can mix 8 and 16 bit devices;
0 is the default.
0 1 = E/ISA level interrupts
0 = edge triggered interrupts; 0 is the default.