Difference between revisions of "DM11-BA Modem Control Multiplexor"

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The '''DM11-BA Modem Control Multiplexor''' is a re-implementation of the [[DM11-BB Modem Control Option]]; instead of plugging into a [[asynchronous serial line]] [[device controller]] [[backplane]] like the -BB, the -BA plugs into a standard [[UNIBUS]] [[Modified UNIBUS Device|MUD]] slot. It is implemented as a single [[DEC card form factor|hex]] [[printed circuit board|card]], the '''M8640'''.
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[[Image:DM11-BA_M8640.jpg|thumb|right|300px|DM11-BA M8640 board]]
  
It connects to a passive distribution panel, either the H317-M or the functionally identical H317-P; the latter has improved [[Interference|EMI]] shielding.
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The '''DM11-BA Modem Control Multiplexor''' allows [[synchronous serial line|synchronous]] and [[asynchronous serial line]]s connected to a [[UNIBUS]] [[device controller]] to be connected to [[modem]]s. It could be set to [[interrupt]] the [[Central Processing Unit|CPU]] when a modem control line (Ring, Carrier, etc) changed state.
  
[[Category: UNIBUS Serial Interfaces]]
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It is a re-implementation of the [[DM11-BB Modem Control Option]]; however, instead of plugging into a controller [[backplane]] like the -BB, the -BA plugs into a standard [[UNIBUS]] [[Modified UNIBUS Device|MUD]] slot. It is [[program compatible]] with the DM11-BB (although a single DM11-BA only supports 8 lines, unlike the DM11-BB, which handled 16).
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It is implemented as a single [[DEC card form factor|hex]] [[printed circuit board|board]], the '''M8640'''. Its [[interrupt vector]] and [[register]] [[address]]es are set by a pair of [[DIP switch]]es (and a [[jumper]] (W1) for one bit of the address, on [[etch]] revision B boards). A [[ ‎UNIBUS priority plug]] is also present.
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It connects, using two [[flat cable]]s plugged into [[Berg connector|Berg headers]] on the board, to a passive distribution panel; either the H317-M or the functionally identical H317-P (the latter has improved [[Interference|EMI]] shielding).
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==Further reading==
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* ''DM11-BA Modem Control Multiplexor'' (YM-C138C-00) - not available online, but in fiche
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==External links==
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* [https://manx-docs.org/collections/antonio/dec/kmsbeug1.pdf KMS11-BD/BE Synchronous Communication Processor User Guide] (EK-KMSBE-UG-001) - contains moderately detailed information on the DM11-BA in various places
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[[Category: UNIBUS Asynchronous Serial Interfaces]]
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[[Category: UNIBUS Synchronous Serial Interfaces]]

Latest revision as of 01:40, 16 February 2023

DM11-BA M8640 board

The DM11-BA Modem Control Multiplexor allows synchronous and asynchronous serial lines connected to a UNIBUS device controller to be connected to modems. It could be set to interrupt the CPU when a modem control line (Ring, Carrier, etc) changed state.

It is a re-implementation of the DM11-BB Modem Control Option; however, instead of plugging into a controller backplane like the -BB, the -BA plugs into a standard UNIBUS MUD slot. It is program compatible with the DM11-BB (although a single DM11-BA only supports 8 lines, unlike the DM11-BB, which handled 16).

It is implemented as a single hex board, the M8640. Its interrupt vector and register addresses are set by a pair of DIP switches (and a jumper (W1) for one bit of the address, on etch revision B boards). A ‎UNIBUS priority plug is also present.

It connects, using two flat cables plugged into Berg headers on the board, to a passive distribution panel; either the H317-M or the functionally identical H317-P (the latter has improved EMI shielding).

Further reading

  • DM11-BA Modem Control Multiplexor (YM-C138C-00) - not available online, but in fiche

External links