The HVS was a cool design - the only real issue if I recall was its limited line buffers meaning it was hard to determine what could be composited in real time,

The HVS was a cool design - the only real issue if I recall was its limited line buffers meaning it was hard to determine what could be composited in real time, so we ended up always rendering to a triple buffer. It also did some amazing scaling in realtime, but this came with some crazy artifacts that were super painful to triage. The occasional "flash of bad pixels" in a live composition screen was really painful. I just remember I wrote the DPI and CPI peripherals that we brought up the HVS with - on a 4MHz FPGA complex, we had YUV camera input scaling up to a WVGA DPI screen running at 60fps on a distributed FPGA platform through the HVS. Fun times.