Compaq PORTABLE 386 - Jumpers E3, E4, E8, and E9 - Select Serial Communications

E7, Pins 1 and 2 Select primary interrupt (IRQ7) (default)
E7, Pins 2 and 3 Select alternate interrupt (IRQ5)
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Table 9-2. Jumpers E3, E4, E8, and E9 - Select Serial Communications
Interface Options
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Jumper Setting Function
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E3, Pins 2 and 3 Select serial interface as COM1 (3FX, IRQ4), and modem
E4, Pins 1 and 2 or second serial interface as COM2 (2FX, IRQ3) (default)
E8, Pins 1 and 2
E8, Pins 3 and 4
E9, Pins 1 and 3
E9, Pins 2 and 4
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E3, Pins 2 and 3 Select serial interface as COM2 (2FX, IRQ3) and modem or
E4, Pins 1 and 2 second serial interface as COM1 (3FX, IRQ4).
E8, Pins 1 and 3
E8, Pins 2 and 4
E9, Pins 1 and 2
E9, Pins 2 and 4
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E3, Pins 2 and 3 Select serial interface as COM1 (3FX, IRQ4), disable
E4, Pins 1 and 1 internal COM2.
E8, Pins 1 and 3
E8, Pins 3 and 4
E9, Pins 1 and 3
E9, Pins 2 and 4
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E3, Pins 1 and 2 Select serial interface as COM2 (2FX, IRQ3), disable
E4, Pins 2 and 3 internal COM1.
E8, Pins 1 and 2
E8, Pins 3 and 4
E9, Pins 1 and 2
E9, Pins 3 and 4
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E3, Pins 2 and 3 Select modem or second serial interface as COM1 (3FX,
E4, Pins 2 and 3 IRQ4), disable internal COM2.
E8, Pins 1 and 3
E8, Pins 2 and 4
E9, Pins 1 and 2
E9, Pins 3 and 4
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E3, Pins 1 and 2 Select modem or second serial interface as COM2 (2FX,
E4, Pins 2 and 3 IRQ3), disable internal COM1.
E8, Pins 1 and 3
E8, Pins 2 and 4
E9, Pins l and 3
E9, Pins 3 and 4
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E3, Pins 1 and 2 Disable both internal serial ports.
E4, Pins 1 and 2
E8, Pins 1 and 2
E8, Pins 3 and 4
E9, Pins 1 and 3
E9, Pins 2 and 4
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