5725A
Instruction Manual
Fan Supply Section |
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The fan supply uses the same transformer secondary windings as the ±15 and ±20V supplies. Its own
Digital Assembly (A5) |
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From a software standpoint, digital circuitry functions as a subset of the 5700A
Figure
∙Microcomputer (Hitachi 6303Y CMOS)
∙External RAM (CMOS static)
∙External ROM
∙EEROM (2Kb X 8)
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∙Power up and reset circuitry
∙Watchdog timer circuitry
∙Front panel LEDs
∙LED decoder and driver
The High Voltage Sense assembly (A6) contains the optoisolator link (guard crossing) to the 5700A Main CPU and the CABLEOFF circuit.
The Current Amplifier assembly (A2) contains the interface to the digital bus (two latches and three relay drivers) and a relay driver chip.
Microcomputer |
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The 6303Y CMOS microcomputer is configured for Mode 1 operation, with external RAM and external ROM. Port 3 provides a common data bus
External RAM |
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External RAM is enabled whenever A15 is high, A14 is low (hex
External ROM |
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The external ROM (U515) is enabled via ROMSEL* whenever A15 and A14 are high (hex