NeXT
Veteran Member
Usually I reserve these blogs for computer related projects but here's something that I've been wanting to get off my bench for a while.
About 10 years I found a rather amazing wireless security system known as the Dicon 9000. The name itself made me feel like it was going to be anything but good.
It appears to of been available in the late 80's and early 90's and came in a grey plastic wedge. It touted a number of integrated features such an electronic voice to help you set the unit up, an internal phone dialer with even more synthesized speech to notify a neighbor or relative or a subscribed security service, a membrane keyboard with seven LED indicators and of course it was wireless. On the back you had a three pin power connection, a jack for the external antenna, telephone, a jack for an external loudspeaker and an additional "Auxiliary" option. A socket for programming security modules into the system was hidden underneath a placecard that you could write down the names and locations of various modules on.
If we pull the unit apart we find that it consists of two multi-layer PCB's. The top board contains the main computer guts and runs on two MC68705 microcontrollers. The TC531000 appears to be a 1 megabit mask ROM. That I can tell from a datasheet it does not contain any security features so nothing says it is impossible to simply drop the chip in a burning station and dump it. Hmm, that seems a bit sketchy given the application in a security system.
The second board seems to contain the logic for the power distribution, RF and phone dialer. You can also see the battery lead for the internal memory protection. The alarm monitors it and asks you to replace it when it runs low. The "Auxiliary" connector seems to pass through a resistor and the trace vanishes under a microphone. The presence of a transistor on the opposite side leads me to suspect that the connector is simply a place where a TTL signal is transmitted for control of other devices such as X10 interfaced lighting or a computer or god knows what. Even the manual never states what this connector was ever used for. Further investigation may be required.
Like any security system there was the option of adding a backup power system. For a premium you purchased a metal box that contained a small amount of voltage regulation and a lead acid battery. It lasts about a day with a good charge. I removed my battery years ago before a move as it was dead and I needed to shed weight for a flight home.
Like I said before the system is wireless. Each component from the keypads to the motion sensors rely on what seems to be a standard module which needs a 9v battery and some sort of incoming signal from the device. In the case of a window or door switch it is just an NC loop.
Each module is supposedly specified by a different type which the computer uses to tell if it is a medical, fire or security incident that has set off the alarm. Internally however it appears the modules are all identical: An RF circuit and a custom sixteen pin DIP.
Now there was more than just keypads, NC switches and IR sensors available. Dicon also supposedly sold options for monitoring temperature, water level, medical pendants, panic buttons and smoke detectors, all of which containing modules you would program into the system and become a surprisingly effective setup.
Unfortunately it seems that Dicon's alarms were never a big hit. As much as I would love to use all the features of the system you can usually only find a small number of keypads, NC loops and motion sensors. I have never seen any of the other options which kind of a letdown as I'd love the additional fire detection and temperature monitoring and run it alongside an X10 Powerhouse controller and a Mastervoice Butler in a Box. I've tried in the past to program an NC loop sensor as a panic button or medical pendant however the main unit simply reports that there is trouble with the module. Is there something specifically different inside those custom IC's from module to module, or are they still universal but it is how they are interacted with externally that defines how they work? It's all a mystery. Dicon appears to of either gone out of business or been bought out years ago, leaving these security systems, a handful of documentation and a small pile of modules floating around garages, ebay and second hand stores.
About 10 years I found a rather amazing wireless security system known as the Dicon 9000. The name itself made me feel like it was going to be anything but good.
It appears to of been available in the late 80's and early 90's and came in a grey plastic wedge. It touted a number of integrated features such an electronic voice to help you set the unit up, an internal phone dialer with even more synthesized speech to notify a neighbor or relative or a subscribed security service, a membrane keyboard with seven LED indicators and of course it was wireless. On the back you had a three pin power connection, a jack for the external antenna, telephone, a jack for an external loudspeaker and an additional "Auxiliary" option. A socket for programming security modules into the system was hidden underneath a placecard that you could write down the names and locations of various modules on.
If we pull the unit apart we find that it consists of two multi-layer PCB's. The top board contains the main computer guts and runs on two MC68705 microcontrollers. The TC531000 appears to be a 1 megabit mask ROM. That I can tell from a datasheet it does not contain any security features so nothing says it is impossible to simply drop the chip in a burning station and dump it. Hmm, that seems a bit sketchy given the application in a security system.
The second board seems to contain the logic for the power distribution, RF and phone dialer. You can also see the battery lead for the internal memory protection. The alarm monitors it and asks you to replace it when it runs low. The "Auxiliary" connector seems to pass through a resistor and the trace vanishes under a microphone. The presence of a transistor on the opposite side leads me to suspect that the connector is simply a place where a TTL signal is transmitted for control of other devices such as X10 interfaced lighting or a computer or god knows what. Even the manual never states what this connector was ever used for. Further investigation may be required.
Like any security system there was the option of adding a backup power system. For a premium you purchased a metal box that contained a small amount of voltage regulation and a lead acid battery. It lasts about a day with a good charge. I removed my battery years ago before a move as it was dead and I needed to shed weight for a flight home.
Like I said before the system is wireless. Each component from the keypads to the motion sensors rely on what seems to be a standard module which needs a 9v battery and some sort of incoming signal from the device. In the case of a window or door switch it is just an NC loop.
Each module is supposedly specified by a different type which the computer uses to tell if it is a medical, fire or security incident that has set off the alarm. Internally however it appears the modules are all identical: An RF circuit and a custom sixteen pin DIP.
Now there was more than just keypads, NC switches and IR sensors available. Dicon also supposedly sold options for monitoring temperature, water level, medical pendants, panic buttons and smoke detectors, all of which containing modules you would program into the system and become a surprisingly effective setup.
Unfortunately it seems that Dicon's alarms were never a big hit. As much as I would love to use all the features of the system you can usually only find a small number of keypads, NC loops and motion sensors. I have never seen any of the other options which kind of a letdown as I'd love the additional fire detection and temperature monitoring and run it alongside an X10 Powerhouse controller and a Mastervoice Butler in a Box. I've tried in the past to program an NC loop sensor as a panic button or medical pendant however the main unit simply reports that there is trouble with the module. Is there something specifically different inside those custom IC's from module to module, or are they still universal but it is how they are interacted with externally that defines how they work? It's all a mystery. Dicon appears to of either gone out of business or been bought out years ago, leaving these security systems, a handful of documentation and a small pile of modules floating around garages, ebay and second hand stores.