23 lines
1.0 KiB
Plaintext
23 lines
1.0 KiB
Plaintext
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AST RESEARCH TECHNICAL BULLETIN TB-0151A 04-11-86
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AST COMMUNICATION BOARDS WITH THE IBM AT AND COMPATIBLES
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AST communication boards use IRQ2 as a factory default interrupt
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setting. The IBM AT, the COMPAQ 286, and the COMPAQ DESKPRO 286
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have two interrupt controller chips: 8259's. IRQ2 is on
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Interrupt Controller, CTLR2, and is a cascading interrupt. A
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cascading interrupt has to travel a longer route before it is
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serviced. Because of this, there may be differences in timing
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between a cascading and non-cascading interrupt. Problems may
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occur if the interrupt takes a longer time to be serviced than
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the communication software expects.
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For this reason, AST suggests that the AST board is set for an
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unused non-cascading interrupt.
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The following AST communication packages use IRQ2: AST-5251/11,
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AST-5251/12, AST-3780, AST-3770, AST-BSC, AST-BSC CLUSTER, AST-
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BSC GATEWAY, AST-SNA, AST-SNA CLUSTER, and AST-SNA GATEWAY.
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