diff options
Diffstat (limited to 'src/mess/drivers/a7800.c')
-rw-r--r-- | src/mess/drivers/a7800.c | 88 |
1 files changed, 44 insertions, 44 deletions
diff --git a/src/mess/drivers/a7800.c b/src/mess/drivers/a7800.c index 75c529c71b2..52394423c3b 100644 --- a/src/mess/drivers/a7800.c +++ b/src/mess/drivers/a7800.c @@ -70,7 +70,7 @@ 2013/11/03 Robert Tuccitto Fixed correctly typo under 26.7 7$. - 2014/11/23 Robert Tuccitto Added NTSC Palette Notes + 2014/11/23 Robert Tuccitto Added NTSC Palette Notes ***************************************************************************/ #include "emu.h" @@ -159,60 +159,60 @@ INPUT_PORTS_END /*************************************************************************** Atari 7800 NTSC Palette Notes: -Palette on a modern flat panel display (LCD, LED, Plasma, etc.) appears -different from a traditional CRT. The most outstanding difference is Hue 1x, -the hue begin point. Hue 1x looks very 'green' (~-60 to -45 degrees - -depending on how poor or well it handles the signal conversion and its -calibration) on a modern flat panel display, as opposed to 'gold' (~-33 -degrees) on a CRT. +Palette on a modern flat panel display (LCD, LED, Plasma, etc.) appears +different from a traditional CRT. The most outstanding difference is Hue 1x, +the hue begin point. Hue 1x looks very 'green' (~-60 to -45 degrees - +depending on how poor or well it handles the signal conversion and its +calibration) on a modern flat panel display, as opposed to 'gold' (~-33 +degrees) on a CRT. -The system's pot adjustment manually manipulates the ratio of blue to -green/blue to red, while the system 'warming-up' causes the palette phase +The system's pot adjustment manually manipulates the ratio of blue to +green/blue to red, while the system 'warming-up' causes the palette phase shift to go higher in degrees. -At power on, the system's phase shift appears as low as ~23 degrees and -after a considerable consistent runtime, can be as high as ~28 degrees. - -In general, the low end of ~23 degrees lasts for maybe several seconds, -whereas higher values such as ~25-27 degrees is the most dominant during -system run time. 180 degrees colorburst takes place at ~25.7 degrees (A -near exact match of Hue 1x and 15x - To the naked eye they appear to be -the same). - -However, if the system is adjusted within the first several minutes of -running, the warm up, consistent system run time, causes Hue 15x (F$) to -become stronger/darker gold (More brown then ultimately red-brown); as well -as leans Hue 14x (E$) more brown than green. Once achieving a phase shift -of 27.7, Hue 14x (E$) and Hue 15x (F$) near-exact match Hue 1x and 2x -respectively. - -Therefore, an ideal phase shift while accounting for the reality of -shifting while warming up, as well as maintaining differences between 1x, -2x and 14x, 15x, would likely fall between a 25.7 and 27.7. Phase shifts -26.2 degrees and 26.7 degrees places Hue 15x (F$) between Hue 1x and -Hue 2x, having 26.2 degrees leaning closer to Hue 1x and 26.7 degrees +At power on, the system's phase shift appears as low as ~23 degrees and +after a considerable consistent runtime, can be as high as ~28 degrees. + +In general, the low end of ~23 degrees lasts for maybe several seconds, +whereas higher values such as ~25-27 degrees is the most dominant during +system run time. 180 degrees colorburst takes place at ~25.7 degrees (A +near exact match of Hue 1x and 15x - To the naked eye they appear to be +the same). + +However, if the system is adjusted within the first several minutes of +running, the warm up, consistent system run time, causes Hue 15x (F$) to +become stronger/darker gold (More brown then ultimately red-brown); as well +as leans Hue 14x (E$) more brown than green. Once achieving a phase shift +of 27.7, Hue 14x (E$) and Hue 15x (F$) near-exact match Hue 1x and 2x +respectively. + +Therefore, an ideal phase shift while accounting for the reality of +shifting while warming up, as well as maintaining differences between 1x, +2x and 14x, 15x, would likely fall between a 25.7 and 27.7. Phase shifts +26.2 degrees and 26.7 degrees places Hue 15x (F$) between Hue 1x and +Hue 2x, having 26.2 degrees leaning closer to Hue 1x and 26.7 degrees leaning closer to Hue 2x. -The above notion would also harmonize with what has been documented for -the colors of 1x, 2x, 14x, 15x on the 7800. 1x = Gold, 2x = Orange, -14x (E$) = Orange-Green. 15x (F$) = Light Orange. Color descriptions are -best measured in the middle of the brightness scale. It should be +The above notion would also harmonize with what has been documented for +the colors of 1x, 2x, 14x, 15x on the 7800. 1x = Gold, 2x = Orange, +14x (E$) = Orange-Green. 15x (F$) = Light Orange. Color descriptions are +best measured in the middle of the brightness scale. It should be mentioned that Green-Yellow is referenced at Hue 13x (D$), nowhere near -Hue 1x. A Green-Yellow Hue 1x is how the palette is manipulated and +Hue 1x. A Green-Yellow Hue 1x is how the palette is manipulated and modified (in part) under a modern flat panel display. -Additionally, the blue to red (And consequently blue to green) ratio -proportions may appear different on a modern flat panel display than a CRT -in some instances for the Atari 7800 system. Furthermore, you may have +Additionally, the blue to red (And consequently blue to green) ratio +proportions may appear different on a modern flat panel display than a CRT +in some instances for the Atari 7800 system. Furthermore, you may have some variation of proportions even within the same display type. - -One side effect of this on the console's palette is that some values of -red may appear too pinkish - Too much blue to red. This is not the same -as a traditional tint-hue control adjustment; rather, can be demonstrated + +One side effect of this on the console's palette is that some values of +red may appear too pinkish - Too much blue to red. This is not the same +as a traditional tint-hue control adjustment; rather, can be demonstrated by changing the blue ratio values via MESS HLSL settings. -Lastly, the Atari 2600 & 5200 NTSC color palettes hold the same hue -structure order and have similar appearance differences that are dependent +Lastly, the Atari 2600 & 5200 NTSC color palettes hold the same hue +structure order and have similar appearance differences that are dependent upon display type. ***************************************************************************/ /*************************************************************************** |