|3M MicroTouch Laptop Digitizer Page (mostly NEC Versa Focused)|
In 2013, I worked for one of the biggest software companies in the world - one that has a campus the size of a small town and starts with an "M". Being a part of that company, I was in the middle of the bleeding edge of the computer industry at the time, and got to see all the wonderous things they were coming up with. That said, the big talk of the time, was making the PC relevant in an era of compact, low-power, touch screen devices - ie Smartphones & tablets, which had been taking marketshare away from the computer for a short time at that point. It seems everybody was talking about these new hybrid tablet/laptop combos like they were some kind of new, amazing thing that would take over the computing world by storm....but let me tell you....this is not hte first time, and likely it won't be the last.....
In the early 1990's, we went through all this same muckety muck as more "normies" started taking to computers and we wanted a more "natural" interface for the comptuer. So "Pen Computing" became a thing, and among the earliest adopters were NEC and Compaq. NEC released their NEC Ultralite SL/25P in 1992, only to bump things up a notch in 1993 with the NEC Ultralite Versa with it's latch detachable, user upgradable screen assembly, offering a "touch w/ pen" option, and also, regardless of screen, you could install the screen backward, flip a latch on top ofthe Versa's screen, and close it up in "Tablet Mode" - just like a Microsoft Surface, Lenovo Yoga, or HP Revolve! It was, indeed, a convertible Tablet PC, 20 years before the term was even coined! So take that computer industry - I see your tricks. Just like when we made the junp from 32-bit to 64-bit I was drawing parallels to when we jumpeed from 16-bit to 32-bit, now I'm drawing a parellel to the touch-screen laptop convertible boom of the early 2010's, and the Pen COmputing "fad" of the early 1990's. NEC and Compaq were not the only ones though, IBM had a ThinkPad offering like this, so did NanTan Computer (75xx and 95xx series), and probably best known was the Dauphin DTR-1, whcih someone AT Microsoft tried to sell me for $60 - and I almost took him up on it. I swear, the 486 era did it all first.
Microtouch is a subsidiary of 3M thaat manufactures these "touch screen" products, and started producing such items in 1984. They are also the company that produced the touch-screen controller on my NEC Versa M/75CP (now HCP as it's 800x600 :P).
Technical Overview of the NEC Versa "P" touch models and how they work
When NEC released the Ultralite Versa in 1993, it was obvious that they intended to create a touch/pen based tablet convertible PC. The screen on ALL of the PC-4xx-x7xx models were detachable by the user by flipping 2 butterfly latches on the upper corners of the base unit. The screen could then be removed and either swapped with another screen, or flipped backwards and then latched into a "tablet mode" type position as we would call it today. Inittially NEC claimed this was for "presentations" - I'm willing to bet NEC was having some complications with their touch screen release, as it did not actually come out until December 1993 at the earliest. It was officially shown in advertising sometimes early on, but a lot of those looked more like a regular non-touch Active Matrix Versa with a regular office-pen stuck on a lanyard for a cable, LOL. But it was obvious, this was NEC's intent the entire time. And even after the item came out - NEC gave you an 800 number to call in their user guide for the Versa E series for touch screens, which then dissappeared, yet they still offered them as late as the late model M/75.
The Screen Assembly for an Active Matrix NEC Versa with the 3M MicroTouch system consists of a special top cover, special bezel with the screen offset by about a centimeter from the right to make room for the touch control board that occupies the entire right side of the screen, the controller board takes up the entire right side of the screen and has the contrast slider built in, the contrast slider and 3M MicroTouch controller is on a separate circuit obviously. The controller cable uses a Type I (Versa Ultralite/E) or Type III (Versa M) controller board with a controller cable from the coupling board to the screen and digitizer circuits that has five or six connectors depending on if it's a Type III or Type I respectively.
The cables coming off the couplign board include the three standard NEC NLxxxxx-xx series LCD panel connectors, and then a fourth connector hangs out just after the entry point on the left side of the screen hinge cover and plugs into a interposter board - which then runs via FFC flat cable to the controller board on the right side of the screen. The LCD Panel is the usual NEC 640x480 LCD Panel (NL6448AC30-03, NL6448AC30-06, or NL6448AC30-10), and the Digitizer used is a 63-4631-00-xx 216x178mm (10.4") Capcitive Touch panel with a 9.5" active area. The touch panel is a Cleartek I product, verified by the model# arrangement, orange banding around the outside, and by the fact that the Cleartek II digitizers tend to have a different molex connector for the "tail". This 5-wire "tail" goes to the upper left hand side of the controller board.
The way this panel works can be explained by it's wiring. There are FIVE wires....top to bottom...
Basically, you have 4 electrodes, one on each corner, and a "ground hoop" etched into the lower layer of glass. When your finger comes in close contact with the screen, each corner registers a certain aamount of capacitance through the "ground hoop", and those measurements translate to the coordinates on screen, usually based of a resource file generated when the calibration sequence was run.
Finding a replacement Cleartek 1 Digitizer in 10.5" format (with 9.4" area) has been incredibly difficult to say the leat. I did find a 9.4" digitizer that literally was too small for the screen, but probably would have worked otherwise, but I returned it because I could not lock it in place using the screen bezel like the old one. The closest replacement I found was on LCD Quote - 63-4421-02 - which I've messaged them twice for dimensions as I'm willing to pay a nice chunk of change keeping a very rare and intersting laptop going, especially with the whole Words+ AAC thing it came with.
Also, there's a touch pen port on the side 1/8" phono, that is used for an active stylus. I might be able to modify a current RJ45 stylus to this.
3M MicroTouch EX Serial Controller Reference Guide