Specifications

Index
-I-
IBM-LPT ......................................................2-16
IBM PC compatibility
...................................... 1-1, 1-9
IBM PC performance compared to ZT 8809A
....................3-3
index registers
.................................................. 6-7
initialization and operation registers
........................... 12-10
initialization control words (ICW1-4)
..........................12-12
input/output addressing
.........................................5-15
installing the ZT 8809A
......................................... 2-7
interrupt controller (8259A)
.................................... 12-2
block diagram
...............................................12-7
cascade buffer/comparator
..................................12-10
Control Logic
............................................... 12-9
EOI commands
............................................ 12-31
functional description
....................................... 12-7
initialization and operation registers
........................ 12-10
initialization control words (ICW1-4)
....................... 12-12
interrupt assignments
.......................................12-22
interrupt in-service register (ISR)
............................ 12-9
interrupt mask register (IMR)
................................ 12-8
interrupt request register (IRR)
.............................. 12-8
I/O port addresses
........................................... 12-3
I/O port addresses and interrupts
............................12-21
operation
.................................................. 12-24
operation control words (OCWs)
........................... 12-16
operation overview
.......................................... 12-4
priority resolver (PR)
........................................12-9
programmable registers
.....................................12-11
read/write control logic
.....................................12-10
RESET
.................................................... 12-34
V20 interrupt vector table
....................................12-5
interrupt enable register (IER)
.................................. 8-30
interrupt ID register (IIR)
...................................... 8-28
interrupt in-service register (ISR)
............................... 12-9
interrupt mask register (IMR)
.................................. 12-8
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