Cyprian Posted December 29, 2020 Share Posted December 29, 2020 According to 7800 Software Guide: All Line RAM is cleared on a line by line basis and BACKGRND color will be displayed if no data is written. Therefore is it possible to enable somehow double-line screen mode or would be possible disable clearing Line-RAM? Quote Link to comment Share on other sites More sharing options...
RevEng Posted December 30, 2020 Share Posted December 30, 2020 It's not possible to enable double-lines purely through software, but you can double up lines using what I refer to as "mirror ram". The Rescue On Fractalus proto uses this. Basically it's on-cart RAM with one of the address lines permanently set low (or skipped) with the effect that each even numbered RAM page is identical to it's neighbouring odd numbered RAM page. When you store graphics in this mirror ram area, when Maria pulls the graphical data it will cause duplicate lines (cutting the Y resolution in half) due to the fact that each line of graphics is stored on consecutive pages. Quote Link to comment Share on other sites More sharing options...
Cyprian Posted December 31, 2020 Author Share Posted December 31, 2020 what a smart idea. anyway, hardware double-line would save some CPU cycles. 1 Quote Link to comment Share on other sites More sharing options...
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