Station Video Mux - Revision history

Peter.eskdale: /* Today */

2014-07-24T21:10:19Z

Today

← Older revision		Revision as of 21:10, 24 July 2014
Line 30:		Line 30:

	After a dramatic hardware failure at Roses 2011 (late summer), the Mux controller begin to get 'picky' about if it liked working on certain days of the week. It was later discovered that some rather large capacitance had bridged across a pair of control lines, making the system purport to work (the Main unit has no way of communicating back to the controller). With no documentation available, it was decided that replacing the controller with a serial interface was the way to go. By 2012, the new control system was implanted into the main unit, making the old external box redundant. As of March 2012, the machine now conforms to the YVP protocol. Several easter eggs have been programmed into the device - please don't go looking for them during a live show...		After a dramatic hardware failure at Roses 2011 (late summer), the Mux controller begin to get 'picky' about if it liked working on certain days of the week. It was later discovered that some rather large capacitance had bridged across a pair of control lines, making the system purport to work (the Main unit has no way of communicating back to the controller). With no documentation available, it was decided that replacing the controller with a serial interface was the way to go. By 2012, the new control system was implanted into the main unit, making the old external box redundant. As of March 2012, the machine now conforms to the YVP protocol. Several easter eggs have been programmed into the device - please don't go looking for them during a live show...

			Following the move to HD in 2013, the Mux (along with most of the SD vision equipment) was reassigned for use in [[docs:Kenobi\|Kenobi]] - an OB flight trolley, which won Best Technical at NaSTA 2014. Following the acquisition of a better (read: not homemade) analogue matrix, the Mux is planned to be retired in Summer/Autumn 2014.
	----		----
	More [[YSTV Technicals]]		More [[YSTV Technicals]]

Mikechislett: /* Today */

2012-08-06T11:23:49Z

Today

← Older revision		Revision as of 11:23, 6 August 2012
Line 28:		Line 28:

	In 2006 the original PIC within the controller was replaced with a PIC18F2455. This was the first step towards giving [[Spider and SchedSeven]] control of the Mux, although currently the USB side of the firmware is still under development.		In 2006 the original PIC within the controller was replaced with a PIC18F2455. This was the first step towards giving [[Spider and SchedSeven]] control of the Mux, although currently the USB side of the firmware is still under development.

			After a dramatic hardware failure at Roses 2011 (late summer), the Mux controller begin to get 'picky' about if it liked working on certain days of the week. It was later discovered that some rather large capacitance had bridged across a pair of control lines, making the system purport to work (the Main unit has no way of communicating back to the controller). With no documentation available, it was decided that replacing the controller with a serial interface was the way to go. By 2012, the new control system was implanted into the main unit, making the old external box redundant. As of March 2012, the machine now conforms to the YVP protocol. Several easter eggs have been programmed into the device - please don't go looking for them during a live show...
	----		----
	More [[YSTV Technicals]]		More [[YSTV Technicals]]

Mikechislett: /* 32 x 4 replacement */

2012-08-06T11:22:53Z

32 x 4 replacement

← Older revision		Revision as of 11:22, 6 August 2012
Line 22:		Line 22:
	All the parts were sourced as free samples from [http://www.maxim-ic.com/ Maxim] under various psuedonyms since the MAX458 crosspoints were actually worth about £40 each.		All the parts were sourced as free samples from [http://www.maxim-ic.com/ Maxim] under various psuedonyms since the MAX458 crosspoints were actually worth about £40 each.

	To avoid the obsolescence problem that the Breaker 88 unit suffered, there were two muxes. A spare circuit board and set of 7 chips ~~are~~ in storage in case of failure, ~~and~~ the controller is made using a cheap reprogrammable micro controller. Some 885 lines of assembler code are all that were required in the micro to perform all of its control functions.		To avoid the obsolescence problem that the Breaker 88 unit suffered, there were two muxes. One live, then a spare circuit board and set of 7 chips were in storage in case of failure, the controller made using a cheap reprogrammable micro controller. Some 885 lines of assembler code are all that were required in the micro to perform all of its control functions.

	After a dramatic hardware failure at Roses 2010 (late summer), the Mux controller begin to get 'picky' about if it liked working on certain days of the week. It was later discovered that some rather large capacitance had bridged across a pair of control lines, making the system purport to work (the Main unit has no way of communicating back to the controller). With no documentation available, it was decided that replacing the controller with a serial interface was the way to go. By 2012, the new control system was implanted into the main unit, making the old external box redundant. As of March 2012, the machine now conforms to the YVP protocol. Several easter eggs have been programmed into the device - please don't go looking for them during a live show.

	==Today==		==Today==

Mikechislett: /* 32 x 4 replacement */

2012-08-06T11:21:33Z

32 x 4 replacement

← Older revision		Revision as of 11:21, 6 August 2012
Line 22:		Line 22:
	All the parts were sourced as free samples from [http://www.maxim-ic.com/ Maxim] under various psuedonyms since the MAX458 crosspoints were actually worth about £40 each.		All the parts were sourced as free samples from [http://www.maxim-ic.com/ Maxim] under various psuedonyms since the MAX458 crosspoints were actually worth about £40 each.

	To avoid the obsolescence problem that the Breaker 88 unit suffered, there ~~are in fact~~ two muxes. A spare circuit board and set of 7 chips are in storage in case of failure, and the controller is made using a cheap reprogrammable micro controller. Some 885 lines of assembler code are all that were required in the micro to perform all of its control functions.		To avoid the obsolescence problem that the Breaker 88 unit suffered, there were two muxes. A spare circuit board and set of 7 chips are in storage in case of failure, and the controller is made using a cheap reprogrammable micro controller. Some 885 lines of assembler code are all that were required in the micro to perform all of its control functions.

			After a dramatic hardware failure at Roses 2010 (late summer), the Mux controller begin to get 'picky' about if it liked working on certain days of the week. It was later discovered that some rather large capacitance had bridged across a pair of control lines, making the system purport to work (the Main unit has no way of communicating back to the controller). With no documentation available, it was decided that replacing the controller with a serial interface was the way to go. By 2012, the new control system was implanted into the main unit, making the old external box redundant. As of March 2012, the machine now conforms to the YVP protocol. Several easter eggs have been programmed into the device - please don't go looking for them during a live show.

	==Today==		==Today==

Sprow: /* 32 x 4 replacement */ Found more chips in the project box

2007-05-30T20:22:28Z

32 x 4 replacement: Found more chips in the project box

← Older revision		Revision as of 20:22, 30 May 2007
Line 22:		Line 22:
	All the parts were sourced as free samples from [http://www.maxim-ic.com/ Maxim] under various psuedonyms since the MAX458 crosspoints were actually worth about £40 each.		All the parts were sourced as free samples from [http://www.maxim-ic.com/ Maxim] under various psuedonyms since the MAX458 crosspoints were actually worth about £40 each.

	To avoid the obsolescence problem that the Breaker 88 unit suffered, there are in fact two muxes. A spare circuit board and set of 4 chips are in storage in case of failure, and the controller is made using a cheap reprogrammable micro controller. Some 885 lines of assembler code are all that were required in the micro to perform all of its control functions.		To avoid the obsolescence problem that the Breaker 88 unit suffered, there are in fact two muxes. A spare circuit board and set of 7 chips are in storage in case of failure, and the controller is made using a cheap reprogrammable micro controller. Some 885 lines of assembler code are all that were required in the micro to perform all of its control functions.

	==Today==		==Today==

Dummy User: link to more YSTV technicals

2007-05-24T19:11:22Z

link to more YSTV technicals

← Older revision		Revision as of 19:11, 24 May 2007
Line 28:		Line 28:

	In 2006 the original PIC within the controller was replaced with a PIC18F2455. This was the first step towards giving [[Spider and SchedSeven]] control of the Mux, although currently the USB side of the firmware is still under development.		In 2006 the original PIC within the controller was replaced with a PIC18F2455. This was the first step towards giving [[Spider and SchedSeven]] control of the Mux, although currently the USB side of the firmware is still under development.
			----
			More [[YSTV Technicals]]

Dummy User: /* 32 x 4 replacement */ I've just found the data on the tuners on distel's site still!

2007-05-24T19:10:34Z

32 x 4 replacement: I've just found the data on the tuners on distel's site still!

← Older revision		Revision as of 19:10, 24 May 2007
Line 16:		Line 16:
	An increase was made to 32 inputs and 4 outputs, along with controller box.		An increase was made to 32 inputs and 4 outputs, along with controller box.

	It included two NICAM stereo terrestrial tuners from [http://www.distel.co.uk/ Display Electronics] which could be retuned under computer control, this was key to the scheduling system and was also intended to make use of the recently upgraded AV network which was stereo capable.		It included two [http://www.distel.co.uk/data_my00.htm NICAM stereo terrestrial tuners] from [http://www.distel.co.uk/ Display Electronics] which could be retuned under computer control, this was key to the scheduling system and was also intended to make use of the recently upgraded AV network which was stereo capable.

	The new mux was briefly installed for a weekend for testing in {{unsure\|2002}} and later withdrawn for minor hardware alterations - it was carried back to Cambridge by train, which included a brief section sliding round in the back of a coach as a derailment had meant trains had to skip part of the journey to Peterborough, making it the most travelled mux in history.		The new mux was briefly installed for a weekend for testing in {{unsure\|2002}} and later withdrawn for minor hardware alterations - it was carried back to Cambridge by train, which included a brief section sliding round in the back of a coach as a derailment had meant trains had to skip part of the journey to Peterborough, making it the most travelled mux in history.
Line 22:		Line 22:
	All the parts were sourced as free samples from [http://www.maxim-ic.com/ Maxim] under various psuedonyms since the MAX458 crosspoints were actually worth about £40 each.		All the parts were sourced as free samples from [http://www.maxim-ic.com/ Maxim] under various psuedonyms since the MAX458 crosspoints were actually worth about £40 each.

	To avoid the obsolescence problem that the Breaker 88 unit suffered, there are ~~infact~~ two muxes. A spare circuit board and set of 4 chips are in storage ~~incase~~ of failure, and the controller is made using a cheap reprogrammable ~~microcontroller~~. Some 885 lines of assembler code are all that is required in the micro to perform all of its control functions.		To avoid the obsolescence problem that the Breaker 88 unit suffered, there are in fact two muxes. A spare circuit board and set of 4 chips are in storage in case of failure, and the controller is made using a cheap reprogrammable micro controller. Some 885 lines of assembler code are all that were required in the micro to perform all of its control functions.

	==Today==		==Today==

Dummy User: Controller PIC been replaced

2007-05-24T09:06:38Z

Controller PIC been replaced

← Older revision		Revision as of 09:06, 24 May 2007
Line 27:		Line 27:
	The outputs originally drove 8 copies of each bus to avoid the need for seperate distribution amplifiers, however in a heavily loaded system some crosstalk was observed. This was misdiagnosed as due to electric fields (!) and the integrated amplifiers chopped out, despite the MAX497 buffers being socketted. It is believed simply increasing the decoupling to the power supply would have resolved the problem and left the unit at its full specification.		The outputs originally drove 8 copies of each bus to avoid the need for seperate distribution amplifiers, however in a heavily loaded system some crosstalk was observed. This was misdiagnosed as due to electric fields (!) and the integrated amplifiers chopped out, despite the MAX497 buffers being socketted. It is believed simply increasing the decoupling to the power supply would have resolved the problem and left the unit at its full specification.

	In ~~2007 it still runs as~~ the ~~main studio video routing crosspoint, but not as~~ the ~~network mux~~. ~~When~~ [[~~BBC Schedula~~]] ~~talked directly to it it performed both tasks~~, ~~it used a simple two wire protocol which proved too difficult to emulate despite~~ the ~~protocol being documented in~~ the ~~service manual, which has presumably since been mislaid~~.		In 2006 the original PIC within the controller was replaced with a PIC18F2455. This was the first step towards giving [[Spider and SchedSeven]] control of the Mux, although currently the USB side of the firmware is still under development.

Sprow: Mux(es) detail

2007-05-23T20:01:13Z

Mux(es) detail

@@ Line 1: / Line 1: @@
-Built by [[Rob Sprowson]]{{unsure| I'm no sure when??}} as both a studio routing crosspoint and a network video control mux.
+==Breaker 88==
-It has 32 inputs and 4 outputs, plus two analogue UHF tuners, all run from a remote control box that hooked up with the [[BBC Schedula]].
+The mammouth broadcast of [[Breaker 88]] was responsible for several new pieces of YSTV equipment being designed and built, a sync pulse generator (SPG) in a 2U rack, and a video multiplexor.
-It still runs as the main studio video routing crosspoint, but not as the network mux, in 2007.

Dummy User: a little intro

2007-02-20T22:01:36Z

a little intro

New page

Built by [[Rob Sprowson]]{{unsure| I'm no sure when??}} as both a studio routing crosspoint and a network video control mux.
It has 32 inputs and 4 outputs, plus two analogue UHF tuners, all run from a remote control box that hooked up with the [[BBC Schedula]].
It still runs as the main studio video routing crosspoint, but not as the network mux, in 2007.