I'm going to use a 640x480 monochrome LCD. Its the smallest that I can find that is big enough to fit the whole screen image. Because of this, the h and v sync signals from the Mac will be useless, so the FPGA will have to create its own for the LCD. Even if the LCD was the same size, I seriously doubt I could use the sync signals directly from the Mac.
The main issue for me is decoding the actual video signal (pin 1 on J4 from the classicmac2 PDF). What I need to know is if it is just 175,000 TTL level pulses in sequence, or is it in some way tied to the sync signals. Basically what I'm asking is if I were to take that video signal and save it to disk, would I be able to reconstruct the bit image from this saved data by simply reading 512 bits of data at a time and turning on the appropriate pixels within that row?
The main issue for me is decoding the actual video signal (pin 1 on J4 from the classicmac2 PDF). What I need to know is if it is just 175,000 TTL level pulses in sequence, or is it in some way tied to the sync signals. Basically what I'm asking is if I were to take that video signal and save it to disk, would I be able to reconstruct the bit image from this saved data by simply reading 512 bits of data at a time and turning on the appropriate pixels within that row?