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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The '''DM11-BA Modem Control Multiplexor''' allows [[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. It is a re-implementation of the [[DM11-BB Modem Control Option]]; instead of plugging into a controller [[backplane]] like the -BB, the -BA plugs into a standard [[UNIBUS]] [[Modified UNIBUS Device|MUD]] slot.
  
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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It is [[program compatible]] with the DM11-BB (although a single DM11-BA only supports 8 lines, unlike the DM11-BB, which handled 16), and is implemented as a single [[DEC card form factor|hex]] [[printed circuit board|board]], the '''M8640'''.
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[[Image:H317BUncovered.jpg|thumb|left|300px|H317-B with cover off]]
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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 one usable with the DM11-BB (such as the H317-B), or the newer H317-M or the functionally identical H317-P (the latter has improved [[Interference|EMI]] shielding).
  
 
[[Category: UNIBUS Serial Interfaces]]
 
[[Category: UNIBUS Serial Interfaces]]

Latest revision as of 09:33, 11 February 2020

The DM11-BA Modem Control Multiplexor allows 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; 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), and is implemented as a single hex board, the M8640.

H317-B with cover off

It connects, using two flat cables plugged into Berg headers on the board, to a passive distribution panel; either one usable with the DM11-BB (such as the H317-B), or the newer H317-M or the functionally identical H317-P (the latter has improved EMI shielding).