As a one day project to kick off the spring weather and hopefully also 3D printer work, I am replacing my ti 86 screen with this screen of same resolution which is coming on Saturday. I believe this will work because the 86 screen has 18 pins and the one on ebay has 20 but that's because it has a backlight anode and cathode. I don't know the 86 screen pinout though. The closest thing I found was this but it was for a ti 83 screen. Thoughts? I'm 90% sure it will work I just don't know what will go where regarding pins and solder.

Haha, I was looking for that exact link just yesterday, nice timing

Cool! I just hope it's the same for the 86. Looking at the two side by side they look pretty similar but who knows for sure?

I remember something about someone taking an 85 screen out, Which i think is similar to the 86 in Pixel dimension and putting it on a 83+. I also remember seeing it for sale on amazon. Let me know how this goes. I might be interested in doing it myself as well.

The way the LCD is addressed is different, so I doubt a TI-86 LCD would work on a TI-83 Plus without rewriting the OS.

Are you thinking of Kerm's TI-82+? https://www.cemetech.net/projects/item.php?id=49
The TI-85 screen is wider than the 83+'s, so swapping them wouldn't work. The TI-82 however does have the same kind of screen, just a different color.

It won't. 86 screen is 128*64 and 83 is 96*64 I think. Ti 85 and 86 screens are identical (or at least compatible.) We'll see how it goes and if anyone finds a way that this wont work.

Unless he sold it on amazon. I don't think so. The guy that sold it had pictures as well I wish i had saved them but didn't think about it at the time. It was a ti-83+ with a ti85 Screen in it.

Edit: I have parts laying around im going to try it right now. I'll be back in about an hour.

As I said before, a TI-85 screen is incompatible with a TI-83+. The two just don't mix. He may have put a TI-85 inside a TI-83+ body, though.

I don't even think this will work. The LCD board of a TI-85 is huge, and would obstruct the screw holes for the housing and likely prohibit the housing from closing without some grinding.

Well. It looks like I am unable to find any kind of data sheet for the ti85/86 displays. I'm still don't think it's impossible to get an 85/86 display to work on an 83 but i don't really feel like pulling out the oscilloscope to figure out the output signals.

It is (impossible).

The only thing wrong with what i'm seeing isn't that it is (impossible) i do a lot of things on a daily basis that are considered "impossible" repairs or just in general things i do for fun. It's more along the lines of not worth figuring out. Nothing is impossible, It just takes thinking a little bit differently.

Well this thread went off course.

Interesting. The estimated delivery was Saturday and it came today.... weird

Well, I got it and it's kinda big. Like just a cm too big to fit inside. The screen itself is the right size but the pcb that it's on is a bit too big. Suggestions? I'm thinking of cutting a hold in the back and have the screen poke through it with the pcb on the outside.

I don't think this counts as a double post.

I emailed ti through the ti cares email to see if they'll give me the pinouts for the ti 86 screen. It looks like a normal 12864 screen but I don't know if it is because the pads aren't labeled. We'll see if ti responds and in the meantime I need to figure out how to get the screen inside the calc.

Let me know if they get back to you with that. I would recommend going to your local walmart and picking up a pair of dikes they're usually only about 1-2 dollars for some cheap ones. You can cut around the fiber glass board if there aren't any traces( hold the board up to a light) you can usually see right through them. If there's no traces present it's usually a safe bet you can just snip off that part of the board.

Ha! Funny you should mention that because I already did
The screen mostly fits inside now save an edge that has traces all the way to the end. I do, however think that the screen is now too tall and would poke out the back of the calc casing if I made a small hole for it.

Ok, so trying to figure out the pinouts on the screen without Ti's email is proving to be extremely difficult and time consuming. Kerm told me yesterday in IRC that they're probably not going to give me that information. I'm not sure really how to continue without knowing where the pins go. I do think, however, that I've found most of them:

From left to right it goes:

VCC
VDD
V0

DB0
DB1
DB2
DB3
DB4
DB5
DB6
DB7

The rest I don't know and I don't even know for sure if those are correct. But I think they are
I'll keep waiting for an email but if anyone with any knowledge of this could post that would be awesome.

EDIT:: Welp, TI was no help. They "do not have any documentation available to provide you for the internal components of the TI-86 or any other calculators we have available."
I highly doubt this is true and they just, like Kerm said, don't want to give it out. I have no idea where to go from here in order to find this information.

Oh, they're telling the truth with (emphasis added) "do not have any documentation available to provide you". I'm sorry that it's frustrating to get that information. Were you able to find the model of the display controlled IC(s) and get their datasheets?

I could find the datasheet for the T6A40 but not the T6A43 or T6A23. I would probably need both to determine the rest of the pins (or possibly all of them) and be sure about it.

I did a live chat with TI just now and they told me to email Ti-Cares after I told them that I already emailed Ti-Cares. I may have to phone them up or just stop trying. To my knowledge no one has done this before so there is no documentation on it which makes it that much harder. I hope I or someone finds that datasheet though. It could prove useful.

I have not yet killed the 86 yet despite many failed screen attempts so that's good

EDIT:: After figuring out which pins go to what on the T6A43 chip with a multimeter it hints towards the 8 data pins being on the very far right seeing as those eight go to the only 8 pins on the chip that are on the top side. Idk if that means anything though.

I still have no idea what the other 7 are. Here's a pic: Thoughts?

Ok, I am officially annoyed at TI.

-- they don't have any online documentation about their calculators. Cemetech has WAY more documentation about their calcs than they do.

-- I emailed ti cares to find out that they have "burned" ("no longer have," yeah, right) their documentation about the ti 86.

-- I live chatted ti to find the same thing, but just by a slightly sassy live chat person.

-- I called 1-800-ticares just to talk to a confused person who had no idea what I was talking about.

This is going to be extremely hard to figure out without help from TI. And with the datasheet for only one of the lcd drivers it's basically going to be trial and error. Not really looking forward to this. Any amount of information about this screen would further my knowledge as apparently I and TI know nothing about it.