28 lines
1.2 KiB
Plaintext
28 lines
1.2 KiB
Plaintext
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AST RESEARCH, INC. TECHNICAL BULLETIN #0813 02-02-93
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=============================================================================
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CUPID 486/33 SYSTEMS AND INTEL OVERDRIVE PROCESSOR UPGRADES
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PROBLEM: After installing an Intel OverDrive processor (ODPR486DX-33)
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into an AST Cupid 486/33 system, POST errors indicating memory
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parity or memory verify errors may occur.
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CAUSE: The problem has been traced to the high input capacitance of
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the Signetics 74F543 transceiver part. The Signetics chip
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input capacitance causes exaggerated signal reflections on the
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data lines between the P-Bus and the microprocessor, resulting
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in distorted waveforms and data errors when the ODPR486DX-33
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accesses the P-Bus.
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AFFECTED
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SYSTEMS: AST Cupid 486/33 Processor boards (part number 202397-0XX).
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SOLUTION: Contact AST Technical Support at 1-800-727-1278 and request
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the Overdrive Termination Module Kit (part number 501182-001).
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