Television (TV) and Video Electronics

My experience in television and video goes back to 1982, when I took a job as an engineer at GTE Sylvania in El Paso Texas. At that time, our GTE Sylvania division was a major supplier of RF cable TV distribution amplifiers. The division also sold cable TV set-top boxes that employed horizontal sync suppression descramblers that were compatible with General Instrument's Jerrold cable TV systems. Below is a photograph of one these set-top boxes.



This set-top box was one of the first set-top boxes to employ an LED display and an IR remote control. GTE sold a lot of these to cable companies. The cable companies would in turn lease the boxes to subscribers. Subscription authorization was managed by a detachable module within the box. Access to the module was controlled through the use of security screws that held the base to the upper part of the set-top box enclosure.

When a subscriber would request a change in his service (give me HBO instead of Showtime) it was necessary to go to the customer's location, retrieve his old box, and install a new box with the proper authorizations. This was known in the industry as "a truck roll". Needless to say, truck rolls were expensive. So in 1982, GTE embarked on a program to produce a two-way addressable module for the converter. The two-way module would be attached in place of the current plastic bottom. In my opinion, the add-on made the set-top box look like a mini-vacuum cleaner. Electronics in the bottom module connected to the existing circuitry in such a way as to enable subscription changes to be communicated to the set-top box over the cable TV system. Not only that, but by using a two-way tranceiver, the cable company could poll the set-top box for status information.

Soon after I went to work for GTE Sylvania, I began designing the head-end equipment that was tasked with communicating with the set-top box. This head-end modem employed a National Semiconductor COP 404 processor (4 bit) and dozens of SSI and MSI chips. I also worked on developing a low cost power supply for the set-top box module. I remember using voltage doublers (or was it triplers?) to produce the high voltage needed to program the (then new) non-volatile memory devices we added to the set-top box. The set-top box nonvolatile memory held the subscription authorization information as well as an address for communication between the set-top box and the headend modem.

Texscan eventually acquired the GTE Sylvania division, and I left to join a number of other GTE Sylvania engineers in a competing start-up company financed by the major supplier of coaxial cable in the US: M/A-COM. There are few jobs that are more fun than being part of a start-up company. Creativity flowed freely. I remember sitting in Bob Sherwood's office, brainstorming with him regarding the operation of the addressable cable system and the protocols we would use. Then I would go off and develop the head-end cable plant interface (our name for the head-end modem) and the set-top box firmware that would make it all happen. We came up with a great system. I don't have any pictures of the equipment I designed, but John Polonchak's head-end scramblers looked like this:



In 1986, M/A-Com decided to sell off its cable and satellite TV divisions to General Instrument. Since General Instrument had two cable TV divisions already, our division was redundant. I interviewed with the two General Instrument CATV divisions. I received offers to join each, but I opted to instead take a job with General Instrument's newly acquired Link-A-Bit satellite TV division in San Diego. So began my foray into satellite TV.

The commercial arm of the Link-A-Bit division (Link-A-Bit also did a lot of government work) was renamed "VideoCipher" after GI acquired it. The name came from the commercial TV encryption devices that were sold under the VideoCipher name. I was hired in as a firmware design engineer, and for about a year I worked on firmware development for a follow-on to the VideoCipher II descrambler, along with a few other projects. Later I embarked on a most interesting journey at General Instrument. The history of VideoCipher is colorful - mainly due to two significant events: the piracy of the VideoCipher II descrambler, and General Instrument's all-digital proposal that led to digital TV as we know it today. VC2 piracy altered my career path significantly, as I eventually became the manager of Security Engineering at VideoCipher. But as I recall, the firmware I developed early on at VideoCipher still managed to find its way into millions of VC2Plus satellite TV descramblers.



Perhaps my firmware code was carried into the VCRS module that followed:



After I left VideoCipher, I kept my hand in video technology. For instance, I wrote the firmware and designed some of the hardware for this frequency agile TV modulator:



This TV modulator was developed for a "smart house" application. The standalone TV modulator was connected to a PC. The PC would send commands to the modulator to tune to a frequency within the CATV frequency band. The input to the modulator was a baseband NTSC TV signal that originated from a video card within the PC. The PC would thereby provide a graphical user interface (GUI) to the homeowner on a chosen home automation TV channel, in much the same way that hotel TV systems provide grahical user interface menus to hotel rooms. The homeowner would navigate the GUI using a handheld RF remote control that I designed as well. The RF signal from the remote control was received, demodulated, and then translated into keyboard codes by the frequency agile TV modulator, which provided the codes to the PC via the keyboard connector. The PC really did not know that the modulator was the source of the keycodes: the PC saw the modulator as a regular PC keyboard. This interface made it convenient for the software designers to test their software. All they needed to do was to use a standard keyboard to simulate input from the RF remote control.

I also designed this video crosspoint switch card for a PC:



I designed this PC card for a company called "Bingo King". The company needed a PC based crosspoint switch so they could provide switchable video feeds to various monitors located throughout a bingo parlor. I used Maxim's 8 X 8 crosspoint switch to do the switching under software control:

Other work I have done has exposed me to digital television technologies including MPEG-2, ATSC, satellite TV, DirectTV, Echostar, DVB, encapsulation of satellite delivered IP content, HDMI, HDCP, LNB technology, TV guide systems, digital cable systems, Motorola Broadband products, Scientific Atlanta (now Cisco) products, VChip, XDS, and hotel TV systems.