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GO MODE VS QUIT MODE
CHAPTER 4
OVERVIEW OF OPERATIONS
NICE has two different states of opera ti on.
In GO mode, NICE executes Z80 instructions at full speed, but only obeys a subset of
its full repertoire of commands. NICE automatically enters the GO mode when you
reset the target system. In QUIT mode, NICE obeys the full set of commands from
the terminal, but it cannot execute instructions at full speed.
Chapters .5 and 6 contain valid GO mode and QUIT mode commands.
When you are not certain of NICE's current mode, you can issue the status command
(~TS
M) from either mode.
If
the bottom line of the display includes the word
"RUNNING," NICE is in the GO mode. Alternatively, depress the "return" key if a
trancated version of the command set is displayed. The Z80 is then in the RUN
mode.
SPECIAL FACTS ABOUT NICE
Because of NICE's compact new design, it behaves somewhat differently from larger
emulators.
Interrupts
NICE has the capability of recognizing Z80 interrupts in the GO mode, but not in the
QUIT mode. In GO mode, interrupts can be enabled or disabled from reaching the
Z80 Microprocessor.
Bus
ReqlleSts
NICE only recognizes Z80 Bus Requests when in the GO mode. In the GO mode, you
can use one of the two GO mode commands to enable or disable Bus Requests to
reach the Z80 Microprocessor. When NICE is in QUIT mode, Bus Requests are not
allowed to reach the Z80 Microprocessor.
13.
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