DSO 32 Home made digital storage oscilloscope

My older DSO designed in 2004 or so. It was partially disassembled for last few years because I needed some components for newer version but now I had some time so I ve finished it. After correction of many design faults it finally works. Since I had only 89Cx051 parallel programmer that time, I ve made it on theese MCUs. It s using three AT89C2051 linked with synchronous serial line. One is used as button interface, second one is used as graphical CPU which adds titles to waveform. Third one is m