CMS:Number One Crossbar Switch: Difference between revisions

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The 1XB was assembled in the museum by volunteers [[CMS:Les Anderson|Les Anderson]] and others. Originally envisioned to be in very limited service, only the minimum amount of equipment was wired up, and until 2019, the switch could only place a maximum of two concurrent calls. This was in part because the volunteers did not contemplate a full working central office, and in part because much of the most important wiring for the machine was cut during its removal. This included the wiring for the Originating Marker route relay bays and ground supplies, which effectively rendered the switch unusable, except for a few very specific operations that it could perform. In addition, it could not originally terminate calls from the museum's [[CMS:Panel Switch|Panel Switch]], as the equipment needed to do that was removed in the early 1970s, when the last of the Seattle panels were retired.

In 2016 volunteers Sarah Autumn and æstrid Smith learned that some No. 1 Crossbar equipment was available from collector [[Jim Day]] in [[Jim's warehouse|his warehouse]] in West Haven, CT. This equipment had been salvaged from the Coney Island 6 exchange on Avenue U in ~~Brookleny~~, NY. Sarah and æstrid ~~travelled~~ to West Haven and retrieved two SD-25013-01 Full Selector terminating senders, and one SD-25012-01 subscriber's sender, which were driven back to Seattle in a minivan. Volunteers Les Anderson, Colin Slater, æstrid Smith and Sarah Autumn installed the terminating senders in 2017, and made the [https://youtube.com/~~3WcrVZsbz6M~~?si=~~jzj8ZiAdEg2P82aG~~ first phone call from the ~~panel~~] in the same year. In the following years, three more terminating senders, and two more subscriber senders were brought back from Jim Day's warehouse to Seattle and installed in the machine.

In 2016 volunteers Sarah Autumn and æstrid Smith learned that some No. 1 Crossbar equipment was available from collector [[Jim Day]] in [[Jim's warehouse|his warehouse]] in West Haven, CT. This equipment had been salvaged from the Coney Island 6 exchange on Avenue U in Brooklyn, NY. Sarah and æstrid traveled to West Haven and retrieved two SD-25013-01 Full Selector terminating senders, and one SD-25012-01 subscriber's sender, which were driven back to Seattle in a minivan. Volunteers Les Anderson, Colin Slater, æstrid Smith and Sarah Autumn installed the terminating senders in 2017, and made the [https://www.youtube.com/watch?v=3WcrVZsbz6M first phone call to the 1XB from the Panel] in the same year. In the following years, three more terminating senders, and two more subscriber senders were brought back from Jim Day's warehouse to Seattle and installed in the machine.

In 2019-2021 the switch underwent major rewiring and upgrades. This work was performed entirely by Sarah Autumn, much of it during the 2020 COVID-19 pandemic. These upgrades were a major overhaul that required taking the switch out of service for a long period of time. Effectively rebuilding the entire machine's topology from scratch, this work increased the call capacity of the 1XB to its theoretical maximum, and fully integrated it with the other switches in the museum, and with our Asterisk box ''[[CMS:Kercheep|kercheep]]'', and the [[CMS:Call simulator|call simulator]].

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 The 1XB was assembled in the museum by volunteers [[CMS:Les Anderson|Les Anderson]] and others. Originally envisioned to be in very limited service, only the minimum amount of equipment was wired up, and until 2019, the switch could only place a maximum of two concurrent calls. This was in part because the volunteers did not contemplate a full working central office, and in part because much of the most important wiring for the machine was cut during its removal. This included the wiring for the Originating Marker route relay bays and ground supplies, which effectively rendered the switch unusable, except for a few very specific operations that it could perform. In addition, it could not originally terminate calls from the museum's [[CMS:Panel Switch|Panel Switch]], as the equipment needed to do that was removed in the early 1970s, when the last of the Seattle panels were retired.
-In 2016 volunteers Sarah Autumn and æstrid Smith learned that some No. 1 Crossbar equipment was available from collector [[Jim Day]] in [[Jim's warehouse|his warehouse]] in West Haven, CT. This equipment had been salvaged from the Coney Island 6 exchange on Avenue U in Brookleny, NY. Sarah and æstrid travelled to West Haven and retrieved two SD-25013-01 Full Selector terminating senders, and one SD-25012-01 subscriber's sender, which were driven back to Seattle in a minivan. Volunteers Les Anderson, Colin Slater, æstrid Smith and Sarah Autumn installed the terminating senders in 2017, and made the [https://youtube.com/3WcrVZsbz6M?si=jzj8ZiAdEg2P82aG first phone call from the panel] in the same year. In the following years, three more terminating senders, and two more subscriber senders were brought back from Jim Day's warehouse to Seattle and installed in the machine.
+In 2016 volunteers Sarah Autumn and æstrid Smith learned that some No. 1 Crossbar equipment was available from collector [[Jim Day]] in [[Jim's warehouse|his warehouse]] in West Haven, CT. This equipment had been salvaged from the Coney Island 6 exchange on Avenue U in Brooklyn, NY. Sarah and æstrid traveled to West Haven and retrieved two SD-25013-01 Full Selector terminating senders, and one SD-25012-01 subscriber's sender, which were driven back to Seattle in a minivan. Volunteers Les Anderson, Colin Slater, æstrid Smith and Sarah Autumn installed the terminating senders in 2017, and made the [https://www.youtube.com/watch?v=3WcrVZsbz6M first phone call to the 1XB from the Panel] in the same year. In the following years, three more terminating senders, and two more subscriber senders were brought back from Jim Day's warehouse to Seattle and installed in the machine.
 In 2019-2021 the switch underwent major rewiring and upgrades. This work was performed entirely by Sarah Autumn, much of it during the 2020 COVID-19 pandemic. These upgrades were a major overhaul that required taking the switch out of service for a long period of time. Effectively rebuilding the entire machine's topology from scratch, this work increased the call capacity of the 1XB to its theoretical maximum, and fully integrated it with the other switches in the museum, and with our Asterisk box ''[[CMS:Kercheep|kercheep]]'', and the [[CMS:Call simulator|call simulator]].