carmel_andrews Posted October 16, 2013 Share Posted October 16, 2013 (edited) Claus...Is there a 'physical limit' to the gfx resolutions the A8 HARDWARE can display (with/out a custom DL or ML trickery), for i am thinking that you could embed some custom trickery in the upgrade to enable much higher gfx resolutions Will it be possible to display more PMG's with the upgrade (again without resorting to some ML trickry) One idea for consideration is a software based blitter and also PMG scaling (like the similar feature on the Lynx, Sprite scaling...but obviously software based) and built into the upgrade Edited October 16, 2013 by carmel_andrews Quote Link to comment Share on other sites More sharing options...
ClausB Posted November 30, 2013 Author Share Posted November 30, 2013 Some timing diagrams to chew on: The normal cycle has lots of dead time from when the address lines are stable to when the data lines need to be stable, because memory circuits were slow back then. ANTIC does not sample the data lines until the end of the cycle, when the Phi2 clock signal goes low. The LEM SRAM is much faster so we can squeeze more read cycles into each ANTIC cycle. The data from Banks 1 and 2 become the enhanced luma, while the Bank 0 data go to ANTIC as before. Corrected text formatting: Normal ANTIC DMA Read Cycle - 559 ns ___________________________ Phi2 \___________________________/ \ _ __________________________________________________ A0-15 _XXXXXX__________________________________________________ _ ___ D0-7 _>-----------------------------------<XXXXXXXXXXXXXXXX___ Double (LEM Stage 1) Read Cycle ___________________________ Phi2 \___________________________/ \ _ ______________________ ___________________________ A0-14 _XXXXXX______________________X___________________________ Bank 1 Bank 0 _ ______________________ __________________________ D0-7 _XXXXXXX______________________X__________________________ Triple (LEM Stage 2) Read Cycle ___________________________ Phi2 \___________________________/ \ _ ______________________ _____________ _____________ A0-14 _XXXXXX______________________X_____________X_____________ Bank 2 Bank 1 Bank 0 _ ______________________ _____________ ____________ D0-7 _XXXXXXX______________________X_____________X____________ Quote Link to comment Share on other sites More sharing options...
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