Oddball military hardware – GRF Control Panel

I bought some more crap; this time another eBay find which appears to be a control panel for a video processing unit that takes the recorded video from a Tornado jet’s onboard VHS video recorder (yes, really!) and exports it to another media format along with some video processing. It has several analog switches and consists of a keyboard with 7 segment displays showing the mission time etc. It was made by GEC-Marconi Avionics (now BAE Systems) in the early 1990’s and is called a “GRF Control Panel” which I think GRF is an acronym for GR Force – as in Tornado GR1 Force. But I’m not really sure. I asked BAE Systems about this unit but it appears to be something they forgot about or contracted it out and stuck their name on it. The boards say Tactus International on them as a clue. That company now seems to be defunct.

Unfortunately it does nothing on it’s own as it is simply a dumb keyboard and display assembly. Internally it is filled with CPLD chips and EPROMS which are used as combinational logic rather than for storing firmware. There’s some ICM7228 LED display driver chips, a few 74xx series chips and that’s about it. The CPLD chips could be possibly resold as they are expensive and obsolete and easily reprogrammed. The rest can go in my spares bin as I managed to control the LED display with an Arduino using the ICM7218 library which works with the ICM7228. The whole thing runs off 5 volts so it was easily powered up and it communicates with the host system via a RS232 port which spits out a continuous stream of garbage. Hmm. It’s not quite as fuckaboutable as I’d thought. I was thinking of connecting it to an Arduino or even a PC to display something useful like the time / date, Youtube stats etc but that’s not gonna work.

I dumped the EPROMS to a file and showed that in the YouTube video below too. As I mentioned above they do not store firmware; rather used as combinational logic to replace a bunch of standard logic gates. This is fairly common in old equipment where an EPROM is used as a substitute for a complex circuit of logic gates. It will be much slower but if speed does not matter but board space does then it’s OK to do this. The dumps might be of some interest to some but they give no clue as to what this thing is (I’m not really sure myself) but it will come in handy for spares. I made a youtube video that shows me talking about the unit and a short capture of the serial data that’s constantly coming out of this thing. That can be found here https://www.youtube.com/watch?v=P-mKmUT1r8Y

So what am I going to do with it? Well like I mentioned in the video the case will come in handy for a project and the CPLD chips could possibly be sold on eBay. The ICM7228 chips can be used for an Arduino or any other microcontroller project as can the seven segment displays. The rest isn’t really much use. But however on the very slim chance that someone who knows what this is reads this article I’d be grateful for any information. It’s likely to be made in very small numbers and has obviously been hand made rather than mass produced. The PCB’s have been designed and made by an external company but the rest is probably hand built. Even the wording above the connectors has been hand drawn and covered with clear laquer – maybe they forgot to add silkscreened logos to the casing?

Hmm. Interesting if not useless little box.

Update to this article – I captured the serial data stream sent from the unit which can be viewed in a text file here.

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