ColecoFan1981

Hi, How does one convert the Y (luminance) and the R-Y / B-Y values of the 15 colors of the TI 9900 series co-processors (the color differences) to RGB? So far, the best-known algorithm to convert RGB to Y/R-Y/B-Y (which comes out as Y-I-Q for old-fashioned NTSC, or as Y-U-V for PAL and modern-day NTSC) is: Y = 0.299R + 0.587G + 0.114B R-Y = R - (0.299R + 0.587G + 0.114B) = 0.701R + 0.587G + 0.114B B-Y = B - (0.299R + 0.587G + 0.114B) = -0.299R - 0.587G + 0.886B As per the TI 9918A/9928A/9929A data manual, the colors are as follows: 0 = Transparent; 1 = Black; 2 = Medium Green; 3 = Light Green; 4 = Dark Blue; 5 = Light Blue; 6 = Dark Red; 7 = Cyan; 8 = Medium Red; 9 = Light Red; A = Dark Yellow; B = Light Yellow; C = Dark Green; D = Magenta; E = Gray; and F = White The values of the TMS-9918A's luminance/chrominance specs and the TMS-992xA's Y luminance and the R-Y and B-Y color differences are given out as voltage ratings from 0.0 to 1.0. The ColecoVision is an 8-bit video game system, so it would utilize voltages ranging that would translate to values anywhere from 0 to 255. For convenience, check out these links: This Week with My Coleco Adam 9611.18 This Week with My Coleco Adam 9612.01 This Week with My Coleco Adam 9702.02 Of course, as Richard F. Drushel had pointed out in the page the 1st link takes you to, TI never bothered to include in the 9900 series data manual the arithmetic signs of the color differences or the unambiguous units for said values, and that he mentions their quote of "percentage of black/white voltage swing" really is ambiguous because the total swing could lie anywhere between 0.75 and 1.0 volts, and that saturated colors never exceed 0.75 volts. Thank you, ~Ben

I would like to know when Konami will follow up on its Arcade Classics Series 15-game anthology for the Nintendo DS. My want list for Volume 2: 1. Super Cobra (May 1981) 2. Frogger (June 1981) 3. Video Hustler (August 1981) 4. Amidar (October 1981) 5. Turtles (November 1981) 6. Jungler (December 1981) 7. Loco-Motion (March 1982) 8. Tutankham (June 1982) 9. Gyruss (March 1983) 10. Badlands (1984) 11. Mikie (October 1984) 12. Konami GT (October 1985) 13. Jackal (October 1986) (US arcade version was called Top Gunner) 14. Blades of Steel (October 1987) 15. Teenage Mutant Ninja Turtles (1989) What do you think of my wanted fifteen games for this next volume? Regards, Ben

I would like to see subject threads on programming the Tomy Tutor. Like the TI-99/4 series before it, the Tutor (or Pyuu-ta in Japan) used a Texas Instruments TMS9918A VDP. Could you folks please consider such threads on these two home computers in the future? Thank you, Ben (ColecoFan1981)