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Interfacing to a real old word processor screen.

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Junior Member level 1
Jul 29, 2009
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I like going through my local thrift stores to find electronics that I can examine and take parts from. I came across a word processor and it works. The LCD screen has a 16 line by 80 character display (A Smith Corona PWP 7000 LT, Cost $700.00 back in 1990 :)

My intention is to build it into a nice debugging display so I can view information in real time while my project is running. I have been working out plans to build a power supply and now I am thinking I want to build a little all in 1 box that has this screen, a USB hub that I can use to plug my ICD 2 into, or for interfacing directly into my PICs once I start experimenting with USB related pic projects, along with a power supply, ect...

Anyway, I have a little 16x2 LCD module (among a few other goodies) ordered, but I have another 2 weeks or so before I get it seeing as how I ordered it from (found this out last time I ordered from them. It's coming from china but they got real good prices on some things).

I have made RGB leds change colors via PWM and used the digital to analog controller to measure temp and made one of those little servo/photosensor doodads that turns torward the light, but otherwise I just started learning how to program pics and build circuits.

I have been reading the documentation on the driver chips and I think I understand the signals I need to send to the screen, but I was thinking that maybe I could snoop the leads going into the module from the main board and look at the exact timings that the serial interface is using. I can type a letter on the keyboard and watch the difference and basically reverse engineer the interface.

Does anyone know if that actually sounds doable? I was thinking I could use a timer or endless loop to read the ports and everytime a port changes state, create a new instance of a structure that contains the status of all the ports im watching, along with the time and/or processor cycle count.

I would think I would be able to "record" a few seconds worth of data (into ram) and then unplug the screen from it's mainboard and plug it into my PIC and playback what I recorded to display exactly what I was typing.

Am I just high or does this sound like something that would work?

The LCD circuit board has 6 HD6100's and 2 HD6103's. Datasheet for them are here: **broken link removed**

There are 10 wires going into the board. I have found a couple of other posts where people where asking about this display, but it l looks like they never made any real progress:

The datasheet mentions over and over using a HD61830 to drive the IC's, but I don't see one on the main circuit board or the display circuit board. I think they are using a custom microcontroller of some kind. There are two IC's on the main board with stickers on them which I can feel a void behind, which leaves me to believe they are those old school UV erasable chips. Probably one is the memory that holds the dictionary, and the other is the microcontroller?

Anyone have any thoughts? I will probably put this project on the back burner until I learn how to generate serial signals to drive my 16x2 module, then work my way up to this big screen.

parts of word processing screen

blueroomelectronics said:
Which microcontroller do you want to debug?

At the moment I have been teaching myself about pics using a pic18f4550

old word processor

Then I'd recommend buying or building a PICkit2 or compatible as they are excellent hardware debuggers / programmers.

word processor screen display

I think you misunderstood my intention. I have an ICD 2, but in order to see variables update I have to pause / step through the code. With a display like this I can send the value of the variables to my screen and see whats going on in real time. It would be an external "watch window".

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