Posted: 1/17/2012 1:06 AM
Post subject: Genesis Aspect Ratio (320x224) (NTSC)
Quote
natt
Editor, Emulator Coder, Site Developer
Joined: 5/11/2011
Posts: 1108
Location: Murka
This website suggests a 6.67mhz pixel clock in 320x224 mode: http://www.atariage.com/forums/topic/179080-atari-sm147-monochrome-monitor-impressions/ This website suggests a 6.70mhz pixel clock in 320x224 mode: http://www.geocities.ws/podernixie/htpc/modes-en.html#smd This website suggests a 53.694175mhz reference clock for the GPU: http://cgfm2.emuviews.com/txt/vdppin.txt If we assume that the pixel clock is generated from simple integer division off the reference clock (quite easy to go), 53.694175/8=6.712mhz which is suspiciously close to both of the other sources. Using this for AR calculation (I've found http://lipas.uwasa.fi/~f76998/video/conversion/ to be pretty good), we get 320/224 * 58320/4739 / (53.694175/8) / 2 = 1.3097... As the "Display Aspect Ratio"