Zamuel_a wrote:Has sync-scroll been used to assist low-CPU-load horizontal scrolling on an ST?
It must be possible since many demo screens has perfect scroll in all direction and 50fps and often in fullscreen to.
Sure - but I'm pretty wary of the fact that what you see happening isn't always what's actually happening e.g. what has been unrolled into memory or what needs done on every scanline (and tying up the CPU) to maintain the scroll.
What I'm interested to know is whether *just* the base address can be moved with syncscroll at a fine grain, and the CPU left free.
I expect it is possible for the reason you stated - probably one or more of those menus couldn't work with the memory available unless it's possible. But finding some details would be interesting. e.g. can it go down to 16 pixels or is it some crazy combination of horrible offsets and copies of the display? And just how horrible does it get