Video ram contention
mode 1 most
mode 2 slightly less
mode 3 and 4 even less
external 1-4mb of ram same as internal rom

does the video ram contention affect any internal or external accelerators?
mayhem quazar 20mhz
velesfot internal 14mhz

neither use dma - does dma need to match accelrator clock speed or internal z80b speed - though not avaailable in case of veelsfot processor socket ripout job

asic cannot include hardware interlaced graphics modes?
does im 2 50hz interrupt interlace sam screens better than 96 odd and 96 even line tinerrupts can?
had to cut htis in too chunks as the 100character limit which is not displayed on screen only appears when you press the post button daft no?
what is the screen resoltuion and the font size what is the connection speed why not answer these first then think about stupid drop down menus that are bigger than the scren and ask what country im in