Zenith Z-100 PC series Service Manual page 79

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Configuration
Switches
Switch SW201 is a pushbutton used to select the CPU clock frequency, as
explained in Table 2-1. Another way to determine the current CPU clock
frequency setting is to enter I CO at the system's Monitor prompt and
press RETURN. The system will respond with two hexadecimal
characters. Convert these hexadecimal characters to binary. If the
most-significant bit of the binary number is 1, the frequency is set at 8
MHz; if the most-significant bit is 0, the frequency is set at 5 MHz.
Table 2-1: CPU Clock Frequency Selection
SWITCH POSITION CPU CLOCK FREQUENCY
IN 4.77 MHz
OUT 8.00 MHz
DIP switch SW202 configures the CPU/memory card to the specific
hardware of the system. Refer to Table 2-2.
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Table 2-2: SW202 Settings
SECTION DEFINITION
Used to determine the frequency of the power supply.
Normal setting is 60 Hz; do not use the 50 Hz setting.
Settings are as follows:
ON
=
60 Hz power supply (factory setting)
OFF
=
50 Hz power supply
Used to determine the device to be used for autoboot.
Settings are as follows:
ON
=
Autoboot from 5.25-inch floppy disk
(factory setting)
OFF
=
Autoboot from rigid disk system
NOTE: This switch cannot be used to defeat the autoboot
feature.
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