24 lines
1.0 KiB
Plaintext
24 lines
1.0 KiB
Plaintext
AST RESEARCH TECHNICAL BULLETIN TB-0163 4-24-86
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ADVANTAGE PARALLEL PORT
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AST Advantage! users have reported interfacing problems between
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the Advantage! parallel port and certain printers. The symptom
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is no output to the printer when connected to the AST Advantage!
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parallel port.
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The problem is an incompatibility between the parallel port
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STROBE output circuit of the AST Advantage! and the printer's
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STROBE input circuit.
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To resolve this incompatibility the IC 74LS05 located at position
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U89 should be replaced with a 7405. This needs to be done to
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insure proper operation. The AST Advantage! board should be
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returned to AST Research for proper rework.
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If the customer's situation does not allow for the return of the
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product to AST for rework, please see detailed instructions of
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this rework in AST FCN number 008.
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