On 13/05/2012 10:14, Andrew Gillen wrote: > There seems to be a lot of talk about timing critical border effects > for the ZX Spectrum. Anyone got any information on achieving the > same sort of effects on the SAM?
It's much the same on SAM, just with different timings and alignment: - longer delay needed from frame interrupt to start of effect - 2 visible blocks per OUT (C),r rather than 3 for the Spectrum - 384T per line rather than 224T/228T to 48/128K - 24 OUTs needed per line rather than 19 for Spectrum - narrower (and possibly taller?) border compared to Spectrum - contended memory+ASIC, rather than just ULA for Spectrum border At least there's only a single SAM model to worry about, and no early/late differences. > imported the result into Sim Coupé, the result encouraged, but > equally frustrated, it created some nice patterns, but not quite the > patterns I wanted. It shouldn't take much to tweak for SAM timings. Chris would probably be up for supporting them as an extra option too, especially if the work has been done to know what's needed :) Doing it all yourself from scratch will probably give you a better idea of how it works. I rarely work out all the timings by hand anymore, and just rely on trial and error. Step through it in the SimCoupe debugger and you'll see current line positions, and it being built up... Si
