Luma Enhancement Module Development

[carmel_andrews]

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

[ClausB]

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____________