I recently decided to clean up my room a bit and found an old laptop from the 90's. Back then, it was running Windows 3.1. The beginning of another technical adventure... :-)
Three or four weeks ago, I found this old laptop, a "MITAC" with an 100 MHz Intel DX-4 CPU, a harddisk with less than a gigabyte storage capacity and a dead battery. It still displayed the startup screen after switching it on - a memory counter checking the 32 megabytes of RAM in the device, but couldn't find a boot disk. Obviously, the harddisk was broken.
What I usually do in this situation is to look for a screwdriver and try to open the device to see what’s inside. Even though I already knew that there was “Intel inside” ;-), I took the laptop apart and separated the components from each other to see what to keep and what not. The LCD screen looked still nice, but it had a connector with 30 or 40 very thin wires and was directly connected to the laptop’s mainboard. Unfortunately, I couldn’t find a datasheet for this model, a Mitsubishi Electric AA10VA6C-ADDD. All I could find were some coarse technical specifications, e.g. that this is a 10 inch, 640 x 480 pixel display and that the price was around USD 1500 when it was introduced in the 90’s. So, I decided to use my scope and figure out what sort of signals the laptop fed into the panel...
I made some notes about which wires seemed to carry the clock, horizontal and vertical sync, power and ground, figured out some details like the 25 MHz pixel clock and 5V supply voltage and googled for datasheets of similar panels. The datasheet of the Sharp LQ64D343 contains a description of the 31 connector pins with the logic signals, and the position of the ones I had measured with the scope seemed to match those in the Sharp datasheet, e.g. hsync on pin 3, vsync on pin 4.
In my diploma thesis 8 years ago, I had gained some experience with a Xilinx Virtex-II FPGA, and somewhere hidden in a drawer, there was still my Spartan-III development board that I had bought shortly afterwards.
It shouldn’t be too difficult to connect the panel to the devleopment board and generate the correct timings to display something on the screen, should it?...