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Made an almost complete implementation of video. Just one row of the diagnostics cartridge seems to be off, showing thw wrong character set.

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This commit is contained in:
Thomas Harte 2016-10-13 19:34:29 -04:00
parent 0ca383ecd1
commit c9962f6502
3 changed files with 42 additions and 8 deletions
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2
Machines/Oric/Oric.cpp
View File

@ -36,7 +36,7 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
*value = _ram[address];
else
{
if(address >= 0xa000) update_video();
if(address >= 0x9800) update_video();
_ram[address] = *value;
}
}

35
Machines/Oric/Video.cpp
View File

@ -48,7 +48,10 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
{
_ink = 0xff;
_paper = 0x00;
_style = 0x00; // TODO: this means standard-size standard charset?
_use_alternative_character_set = _use_double_height_characters = _blink_text = false;
set_character_set_base_address();
if(!_counter) _frame_counter++;
}
State new_state = Blank;
@ -74,7 +77,7 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
if(new_state == Pixels) {
uint8_t pixels, control_byte;
if(_is_graphics_mode)
if(_is_graphics_mode && _counter < 200*64)
{
control_byte = pixels = _ram[0xa000 + (_counter >> 6) * 40 + h_counter];
}
@ -82,14 +85,18 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
{
int address = 0xbb80 + (_counter >> 9) * 40 + h_counter;
control_byte = _ram[address];
pixels = _ram[_character_set_base_address + control_byte * 8 + ((_counter >> 6) & 7)];
int line = _use_double_height_characters ? ((_counter >> 7) & 7) : ((_counter >> 6) & 7);
pixels = _ram[_character_set_base_address + control_byte * 8 + line];
}
uint8_t inverse_mask = (control_byte & 0x80) ? 0x77 : 0x00;
if(_blink_text) inverse_mask ^= (_frame_counter&32) ? 0x77 : 0x00;
if((control_byte & 0x7f) >= 32)
{
uint8_t colours[2] = {
(control_byte & 0x80) ? _ink : _paper,
(control_byte & 0x80) ? _paper : _ink,
(uint8_t)(_paper ^ inverse_mask),
(uint8_t)(_ink ^ inverse_mask),
};
_pixel_target[0] = (colours[(pixels >> 4)&1] & 0x0f) | (colours[(pixels >> 5)&1] & 0xf0);
@ -108,6 +115,15 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
case 0x05: _ink = 0x55; break;
case 0x06: _ink = 0x33; break;
case 0x07: _ink = 0x77; break;
case 0x08: case 0x09: case 0x0a: case 0x0b:
case 0x0c: case 0x0d: case 0x0e: case 0x0f:
_use_alternative_character_set = (control_byte&1);
_use_double_height_characters = (control_byte&2);
_blink_text = (control_byte&4);
set_character_set_base_address();
break;
case 0x10: _paper = 0x00; break;
case 0x11: _paper = 0x44; break;
case 0x12: _paper = 0x22; break;
@ -116,9 +132,16 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
case 0x15: _paper = 0x55; break;
case 0x16: _paper = 0x33; break;
case 0x17: _paper = 0x77; break;
case 0x18: case 0x19: case 0x1a: case 0x1b:
case 0x1c: case 0x1d: case 0x1e: case 0x1f:
_is_graphics_mode = (control_byte & 4);
_is_sixty_hertz = !(control_byte & 2);
break;
default: break;
}
_pixel_target[0] = _pixel_target[1] = _pixel_target[2] = _paper;
_pixel_target[0] = _pixel_target[1] = _pixel_target[2] = (uint8_t)(_paper ^ inverse_mask);
}
_pixel_target += 3;
}

13
Machines/Oric/Video.hpp
View File

@ -34,9 +34,20 @@ class VideoOutput {
uint8_t *_pixel_target;
// Registers
uint8_t _ink, _style, _paper;
uint8_t _ink, _paper;
int _character_set_base_address;
inline void set_character_set_base_address()
{
if(_is_graphics_mode) _character_set_base_address = _use_alternative_character_set ? 0x9c00 : 0x9800;
else _character_set_base_address = _use_alternative_character_set ? 0xb800 : 0xb400;
}
bool _is_graphics_mode;
bool _is_sixty_hertz;
bool _use_alternative_character_set;
bool _use_double_height_characters;
bool _blink_text;
};
}