mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-23 21:28:06 +11:00
57fd14b0b3
In CURSOR!, I was using a write commande to read from VRAM and the emulator didn't properly behave and did as if everything was fine. The result on a real SMS was that the cursor would contain the inverted glyph of the contents of the *old* cursor position.
92 lines
2.0 KiB
C
92 lines
2.0 KiB
C
#include <stdio.h>
|
|
#include <string.h>
|
|
#include "tms9918.h"
|
|
|
|
static uint8_t COLORS[0x10] = { // TODO: put actual color codes
|
|
0, // transparent
|
|
0, // black
|
|
1, // medium green
|
|
1, // light green
|
|
1, // dark blue
|
|
1, // light blue
|
|
1, // dark red
|
|
1, // cyan
|
|
1, // medium red
|
|
1, // light red
|
|
1, // dark yellow
|
|
1, // light yellow
|
|
1, // dark green
|
|
1, // magenta
|
|
1, // gray
|
|
1, // white
|
|
};
|
|
|
|
void tms_init(TMS9918 *tms)
|
|
{
|
|
memset(tms->vram, 0, TMS_VRAM_SIZE);
|
|
memset(tms->regs, 0, 0x10);
|
|
tms->has_cmdlsb = false;
|
|
tms->curaddr = 0;
|
|
tms->databuf = 0;
|
|
tms->width = 40*6;
|
|
tms->height = 24*8;
|
|
}
|
|
|
|
uint8_t tms_cmd_rd(TMS9918 *tms)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
void tms_cmd_wr(TMS9918 *tms, uint8_t val)
|
|
{
|
|
if (!tms->has_cmdlsb) {
|
|
tms->cmdlsb = val;
|
|
tms->has_cmdlsb = true;
|
|
return;
|
|
}
|
|
tms->has_cmdlsb = false;
|
|
if ((val & 0xc0) == 0x80) {
|
|
// set register
|
|
tms->regs[val&0xf] = tms->cmdlsb;
|
|
} else {
|
|
// VRAM
|
|
tms->curaddr = ((val&0x3f) << 8) + tms->cmdlsb;
|
|
if ((val & 0x40) == 0) { // reading VRAM
|
|
tms->databuf = tms->vram[tms->curaddr];
|
|
}
|
|
}
|
|
}
|
|
|
|
uint8_t tms_data_rd(TMS9918 *tms)
|
|
{
|
|
return tms->databuf;
|
|
}
|
|
|
|
void tms_data_wr(TMS9918 *tms, uint8_t val)
|
|
{
|
|
tms->databuf = val;
|
|
if (tms->curaddr < TMS_VRAM_SIZE) {
|
|
tms->vram[tms->curaddr++] = val;
|
|
}
|
|
}
|
|
|
|
// Returns a 8-bit RGB value (0b00bbggrr)
|
|
uint8_t tms_pixel(TMS9918 *tms, uint16_t x, uint16_t y)
|
|
{
|
|
if ((tms->regs[1]&0x18) == 0x10 && (tms->regs[0]&0x40) == 0) {
|
|
// Text mode
|
|
uint16_t nameoff = (tms->regs[2] & 0xf) << 10;
|
|
uint16_t patternoff = (tms->regs[4] & 0x7) << 11;
|
|
uint8_t nameid = tms->vram[nameoff+(((y/8) * 40) + (x/6))];
|
|
uint8_t patternline = tms->vram[patternoff+(nameid*8)+(y%8)];
|
|
uint8_t color = tms->regs[7];
|
|
if ((patternline>>(8-(x%6)))&1) {
|
|
color >>= 4;
|
|
}
|
|
color &= 0xf;
|
|
return color;
|
|
} else { // unsupported mode
|
|
return 0;
|
|
}
|
|
}
|