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02156: naughtyb: Wrong RESNET calculation of the green component.

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* RGB circuit is driven by a 7407 open collector IC
This commit is contained in:
Couriersud 2008-09-22 20:51:04 +00:00
parent 990ef98b53
commit 42dc413890
1 changed files with 27 additions and 33 deletions
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60
src/mame/video/naughtyb.c
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@ -42,7 +42,26 @@ static const rectangle rightvisiblearea =
0*8, 28*8-1
};
static const res_net_decode_info naughtyb_decode_info =
{
2, /* two proms */
0, /* start at 0 */
255, /* end at 255 */
/* R, G, B, R, G, B */
{ 0, 0, 0, 256, 256, 256}, /* offsets */
{ 0, 2, 1, -1, 1, 0}, /* shifts */
{0x01,0x01,0x01,0x02,0x02,0x02} /* masks */
};
static const res_net_info naughtyb_net_info =
{
RES_NET_VCC_5V | RES_NET_VBIAS_5V | RES_NET_VIN_OPEN_COL,
{
{ RES_NET_AMP_NONE, 130, 270, 2, { 270, 1 } }, /* no resistor for bit1 */
{ RES_NET_AMP_NONE, 130, 270, 2, { 270, 1 } }, /* no resistor for bit1 */
{ RES_NET_AMP_NONE, 130, 270, 2, { 270, 1 } } /* no resistor for bit1 */
}
};
/***************************************************************************
@ -50,7 +69,8 @@ static const rectangle rightvisiblearea =
Naughty Boy has two 256x4 palette PROMs, one containing the high bits and
the other the low bits (2x2x2 color space).
The palette PROMs are connected to the RGB output this way:
The palette PROMs are connected to a 7407 (hex open collector buffer),
which in turn is connected to the RGB output this way:
bit 3 --
-- 270 ohm resistor -- GREEN
@ -62,50 +82,24 @@ static const rectangle rightvisiblearea =
-- BLUE
bit 0 -- RED
plus 270 ohm pullup and pulldown resistors on all lines
plus 130 ohm pullup and 270 ohm pulldown resistors on all lines
***************************************************************************/
PALETTE_INIT( naughtyb )
{
/* note: there is no resistor on second PROM so we define second resistance as 0 */
static const int resistances[2] = { 270, 0 };
double rweights[2], gweights[2], bweights[2];
rgb_t *rgb;
int i;
/* compute the color output resistor weights */
compute_resistor_weights(0, 255, -1.0,
2, resistances, rweights, 270, 270,
2, resistances, gweights, 270, 270,
2, resistances, bweights, 270, 270);
rgb = compute_res_net_all(color_prom, &naughtyb_decode_info, &naughtyb_net_info);
for (i = 0; i < 0x100; i++)
{
int bit0, bit1;
int r, g, b;
int swapped_i;
palette_set_color(machine, BITSWAP8(i,5,7,6,2,1,0,4,3), rgb[i]);
/* red component */
bit0 = (color_prom[i | 0x000] >> 0) & 0x01;
bit1 = (color_prom[i | 0x100] >> 0) & 0x01;
r = combine_2_weights(rweights, bit0, bit1);
/* green component */
bit0 = (color_prom[i | 0x000] >> 2) & 0x01;
bit1 = (color_prom[i | 0x100] >> 2) & 0x01;
g = combine_2_weights(gweights, bit0, bit1);
/* blue component */
bit0 = (color_prom[i | 0x000] >> 1) & 0x01;
bit1 = (color_prom[i | 0x100] >> 1) & 0x01;
b = combine_2_weights(bweights, bit0, bit1);
swapped_i = BITSWAP8(i,5,7,6,2,1,0,4,3);
palette_set_color(machine, swapped_i, MAKE_RGB(r, g, b));
}
palette_normalize_range(machine->palette, 0, 255, 0, 255);
}
/***************************************************************************
Start the video hardware emulation.