56 lines
2.0 KiB
Plaintext
56 lines
2.0 KiB
Plaintext
AST RESEARCH TECHNICAL BULLETIN TB-0005 4-23-84
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SETTING CLOCK FREQUENCY FOR SIXPAKPLUS FASTER OR SLOWER
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CAUTION: We suggest that you leave the factory configuration
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alone. But, if you must, here is the pertinent
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information you'll need.
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How to set frequency of SixPak clock, so as to slow frequency
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down or speed frequency up.
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First, a few points of reference:
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1. Clock chip U66 on SixPak board, pin 11 is the pin
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responsible for checking frequency (see Diagram 1.0).
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The notched end of the chip is the location of pin 1
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(see Diagram 1.1).
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2. Variable Capacitor; C86 located next to clock chip (see
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Diagram 2.0). Turning this clockwise speeds up frequency
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and turning counter-clockwise slows it down (see Diagram
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2.1).
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The recommended frequency range is 30.5171-30.5175KHZ.
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Above 30.5175, or clockwise, is faster; and below
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30.5171 KHZ, or counter-clockwise, is slower (see
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Diagram 2.2).
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3. Setting Frequency Counter: Racal-Dana 9906 or
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Equivalent.
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A) Time Base 104
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B) Period A
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C) Delay Out
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D) DC
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E) Start and Stop on Leading Edge
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4. Checking voltage of battery pin 24 of clock chip and
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minus side of battery holder (see Diagram 3.0).
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Minimum voltage at pin 24 should be no lower than 2.3
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volts, and the battery itself should be 3.0 volts; 2.8
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at the lowest.
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NOTE: As a portion of the data is in pictorial form, it is not
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included here. To obtain a complete copy of this technical
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bulletin, contact:
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AST RESEARCH, INC.
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2121 Alton Avenue
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Irvine, California 92714
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ATTENTION: Product Support
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(Technical Bulletin)
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