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CPU Reset
DI Instruction Execution
EI Instruction Execution
LD A,I Instruction Execution *
LD A,R instruction Execution *
Accept NMI
RETN Instruction Execution IFF2 *
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0 0 Maskable Interrupt, INT Disabled
0 0 Maskable INT Disabled
1 1 Maskable, INT Enabled
IFF2 “ñ Parity Flag
*
IFF2 “ñ Parity Flag
*
Maskable ñ Interrupt
0 *
IFF2 “ñ indicates completion of non-
maskable interrupt service routine.
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