Texas Instruments 9918/9928(a) graphics

[newcoleco]

Enjoy learning about graphiques modes, sprites and characters!

 

 

Note : The first video is only 1 minute long and it's for all audiance. The second one is 4 minutes and it's more for programmers (colecovision, coleco adam, ti99/4a, msx-1, etc.)

[Pixelboy]

Very nice!

[newcoleco]

A too short video about how to make a title screen.

Youtube :

DailyMotion : http://www.dailymotion.com/newcoleco/video/9099103

[classics]

Nice videos, will you be making more?

 

Steve

[Pixelboy]

Nice videos, will you be making more?

Yeah, I like them too.

 

One video I would really like to see is one that explains sound output on the CV. It would probably be more difficult to do because you'd have to figure out a way to clearly explain things graphically on screen, in parallel to playing audio examples. But a well-done video would go a long way in clarifying this particular subject.

[newcoleco]

Nice videos, will you be making more?

Yeah, I like them too.

Thanks! I will try to make some more video about graphics.

 

One video I would really like to see is one that explains sound output on the CV. It would probably be more difficult to do because you'd have to figure out a way to clearly explain things graphically on screen, in parallel to playing audio examples. But a well-done video would go a long way in clarifying this particular subject.

During the Adamcon this summer (mid-june), I will talk about minigames cartridges and about sounds, with the help of my os7 sound bank applet.

[Pixelboy]

During the Adamcon this summer (mid-june), I will talk about minigames cartridges and about sounds, with the help of my os7 sound bank applet.

Like you did at the 2005 Arcadia Festival? Been there, done that.

Edited May 23, 2008 by Pixelboy

[newcoleco]

During the Adamcon this summer (mid-june), I will talk about minigames cartridges and about sounds, with the help of my os7 sound bank applet.

Like you did at the 2005 Arcadia Festival? Been there, done that.

Well, this time, I will try to specifically not talk aobut programming, and that will be tough.

[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

Edited January 26, 2009 by ColecoFan1981

[newcoleco]

Well, if you did read these web pages, then you know as much on the subject than myself.

 

The only thing I can say, and it's not useful for you, is that the color rendering on a PC monitor screen with tv card is exactly these colors that Dr.D. calculated based on technical informations. But I did experiment color saturation rendering when playing the coleco games with a real old tv set and also with a Commodore monitor (a classic). I know... it doesn't answer your question.