One of my tutors at uni would get us to do presentations on old papers. I remember one that described a novel very early GUI system. They built the hardware by

One of my tutors at uni would get us to do presentations on old papers. I remember one that described a novel very early GUI system. They built the hardware by basically wiring two machines together at the bus level (one was essentially the graphics card), and adding a bunch of additional instructupions using TTL logic chips, it was immensely impressive.