Tone ID on a Classic IDX???

[Huizer]

Hi all, I enjoy cruising this site every few weeks to see whats up. I have built the Proscan PI and enjoy learning about electronics and metal detectors. Right now I currently own a Whites Classic IDX. I was thinking about putting a back light in the display so I can see it better when it starts getting dark. So I took apart the display and there is plenty of room in there for a backlight. Ok, so what? Thats simple stuff. What I am posting here for is a little shed knowledge on tone ID. I was looking at the LCD screen. Its a plain simple screen with 8 icon blocks. There are 9 pins going into it...i guess 8 for the block signals and 1 for the common. What I would like to know is do you think its possible to tap into these 8 signal pins with something like a sensitive SCR and a quick tone generating circuit with 8 different resistances one for each LCD signal block? My goal would be to have a different tone for each of the 8 signal blocks. Whenever any LCD block is lit there would also be a tone. What do you think?
Could it be done? I just think that tone ID would be better than the single tone that the IDX produces now.

Also, anyone have any homebrew schematics for mods on the IDX? I keep hearing about some guy named Mr. Bill. He must gaurd what he does very carefully because I cant find anything on the net about what he does to the IDX.

So if anyone has ideas on what I posted please let me know...

Thanks, Huizer.

[Carl-NC]

You need to hook a voltmeter to the pins to see if they do what you think. I expect that the icon blocks are bitmaps, and the 9 pins are for an 8-bit address (plus ground) that do a whole lot more than just light up a single icon per pin. I might be wrong... I don't have an ID/IDX, so I don't even know what the display looks like.

I think I've seen a schematic of the mod Mr. Bill does, but don't remember where. The GB & threshold are pretty easy, not sure what the boost involved.

- Carl

[Siliquae_Sid]

OK here's a simply solution.

First, check that each "block" turns on when the corresponding input line goes high. As only ONE block is "on" at any on time (the display is not like a bargraph) then you can use each input line to switch a CD4066 quad bilateral switch, connected to a resistor, then connected to a 555 timer/tone generator.

When each individual block lights, the corresponding value resistor is switched into the timing circuit of the 555, this gives you a different tone. tracing the Classic's audio circuit, you could cut the track and feed the output from the 555 into the Classic's audio amp, thus using the same headphoner socket and/ or loudspeaker.

If you need a circuit for this, you will have to trace out the classics diaply circuit for me then I can put something together for you.

I could also tell you what the mod for boost is, but as I got this of Mr/ Bill, and it's his livelihood, I don't think he'd be too pleased if I did.

[mattw]

Hey, could you email me so we can chat about this idea for a tone id mod. I like the sound of it and want to try it.

Matt