From 72019d0ea3e8b702437927f1e4b68590164478fe Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Mon, 11 Jan 2016 22:08:30 -0500 Subject: [PATCH] Made an attempt to get video output correct. --- Machines/Electron/Electron.cpp | 141 ++++++++++++++++++++++++++++----- Machines/Electron/Electron.hpp | 3 + 2 files changed, 123 insertions(+), 21 deletions(-) diff --git a/Machines/Electron/Electron.cpp b/Machines/Electron/Electron.cpp index 4c2fb0b14..0caccc2a7 100644 --- a/Machines/Electron/Electron.cpp +++ b/Machines/Electron/Electron.cpp @@ -20,9 +20,11 @@ static const int crt_cycles_per_line = crt_cycles_multiplier * cycles_per_line; Machine::Machine() : _interruptControl(0), _frameCycles(0), - _outputPosition(0) + _outputPosition(0), + _currentOutputLine(0) { memset(_keyStates, 0, sizeof(_keyStates)); + memset(_palette, 0xf, sizeof(_palette)); _crt = new Outputs::CRT(crt_cycles_per_line, 312, 1, 1); _interruptStatus = 0x02; setup6502(); @@ -125,11 +127,56 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin printf("Counter\n"); break; case 0x7: - printf("Misc. control\n"); + if(!isReadOperation(operation)) + { + _screenMode = ((*value) >> 3)&7; + if(_screenMode == 7) _screenMode = 4; + switch(_screenMode) + { + case 0: case 1: case 2: _screenModeBaseAddress = 0x3000; break; + case 3: _screenModeBaseAddress = 0x4000; break; + case 4: case 5: _screenModeBaseAddress = 0x5800; break; + case 6: _screenModeBaseAddress = 0x6000; break; + } + printf("Misc. control\n"); + } break; default: - update_display(); -// printf("Palette\n"); + { + if(!isReadOperation(operation)) + { + update_display(); + + static const int registers[4][4] = { + {10, 8, 2, 0}, + {14, 12, 6, 4}, + {15, 13, 7, 5}, + {11, 9, 3, 1}, + }; + const int index = (address >> 1)&3; + const uint8_t colour = ~(*value); + if(address&1) + { + _palette[registers[index][0]] = (_palette[registers[index][0]]&3) | ((colour >> 1)&4); + _palette[registers[index][1]] = (_palette[registers[index][1]]&3) | ((colour >> 0)&4); + _palette[registers[index][2]] = (_palette[registers[index][2]]&3) | ((colour << 1)&4); + _palette[registers[index][3]] = (_palette[registers[index][3]]&3) | ((colour << 2)&4); + + _palette[registers[index][2]] = (_palette[registers[index][2]]&5) | ((colour >> 4)&2); + _palette[registers[index][3]] = (_palette[registers[index][3]]&5) | ((colour >> 3)&2); + } + else + { + _palette[registers[index][0]] = (_palette[registers[index][0]]&6) | ((colour >> 7)&1); + _palette[registers[index][1]] = (_palette[registers[index][1]]&6) | ((colour >> 6)&1); + _palette[registers[index][2]] = (_palette[registers[index][2]]&6) | ((colour >> 5)&1); + _palette[registers[index][3]] = (_palette[registers[index][3]]&6) | ((colour >> 4)&1); + + _palette[registers[index][0]] = (_palette[registers[index][0]]&5) | ((colour >> 2)&2); + _palette[registers[index][1]] = (_palette[registers[index][1]]&5) | ((colour >> 1)&2); + } + } + } break; } } @@ -176,6 +223,7 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin update_display(); _frameCycles = 0; _outputPosition = 0; + _currentOutputLine = 0; } if(_frameCycles == 128*128) signal_interrupt(InterruptRealTimeClock); if(_frameCycles == 284*128) signal_interrupt(InterruptDisplayEnd); @@ -247,10 +295,12 @@ inline void Machine::update_display() { // on lines prior to 28 or after or equal to 284, or on a line that is equal to 8 or 9 modulo 10 in a line-spaced mode, // the line is then definitely blank. - if( - (current_line < 28 || current_line >= 284) -// || (((current_line - 28)%10) > 7) - ) + bool isBlankLine = + ((_screenMode == 3) || (_screenMode == 6)) ? + ((current_line < 28 || current_line >= 277) || (((current_line - 28)%10) > 7)) : + ((current_line < 28 || current_line >= 284)); + + if(isBlankLine) { if(line_position == 9) { @@ -276,19 +326,67 @@ inline void Machine::update_display() if(line_position >= 24 && line_position < 104) { - if(_currentLine) + if(_currentLine && ((_screenMode < 4) || !(line_position&1))) { - if(!(line_position&1)) + if(_currentScreenAddress&32768) { - uint8_t pixels = _ram[_currentScreenAddress]; - _currentScreenAddress += 8; - int output_ptr = (line_position - 24) << 3; + _currentScreenAddress = _screenModeBaseAddress + (_currentScreenAddress&32767); + } + uint8_t pixels = _ram[_currentScreenAddress]; + _currentScreenAddress = _currentScreenAddress+8; + int output_ptr = (line_position - 24) << 3; - for(int c = 0; c < 16; c+=2) - { - _currentLine[output_ptr + c] = _currentLine[output_ptr + c + 1] = (pixels&0x80) ? 0 : 7; - pixels <<= 1; - } + switch(_screenMode) + { + case 0: + case 3: + for(int c = 0; c < 8; c++) + { + uint8_t colour = (pixels&0x80) >> 4; + _currentLine[output_ptr + c] = _palette[colour]; + pixels <<= 1; + } + break; + + case 1: + for(int c = 0; c < 8; c += 2) + { + uint8_t colour = ((pixels&0x80) >> 4) | ((pixels&0x08) >> 2); + _currentLine[output_ptr + c + 0] = _currentLine[output_ptr + c + 1] = _palette[colour]; + pixels <<= 1; + } + break; + + case 2: + for(int c = 0; c < 8; c += 4) + { + uint8_t colour = ((pixels&0x80) >> 4) | ((pixels&0x20) >> 3) | ((pixels&0x08) >> 2) | ((pixels&0x02) >> 1); + _currentLine[output_ptr + c + 0] = _currentLine[output_ptr + c + 1] = + _currentLine[output_ptr + c + 2] = _currentLine[output_ptr + c + 3] = _palette[colour]; + pixels <<= 1; + } + break; + + case 5: + for(int c = 0; c < 16; c += 4) + { + uint8_t colour = ((pixels&0x80) >> 4) | ((pixels&0x08) >> 2); + _currentLine[output_ptr + c + 0] = _currentLine[output_ptr + c + 1] = + _currentLine[output_ptr + c + 2] = _currentLine[output_ptr + c + 3] = _palette[colour]; + pixels <<= 1; + } + break; + + default: + case 4: + case 6: + for(int c = 0; c < 16; c += 2) + { + uint8_t colour = (pixels&0x80) >> 4; + _currentLine[output_ptr + c] = _currentLine[output_ptr + c + 1] = _palette[colour]; + pixels <<= 1; + } + break; } } _outputPosition++; @@ -296,9 +394,10 @@ inline void Machine::update_display() if(line_position == 104) { - if(!((current_line - 27)&7)) + _currentOutputLine++; + if(!(_currentOutputLine&7)) { - _startLineAddress += 40*8 - 7; + _startLineAddress += ((_screenMode < 4) ? 80 : 40)*8 - 7; } else _startLineAddress++; @@ -320,7 +419,7 @@ const char *Machine::get_signal_decoder() "vec4 sample(vec2 coordinate)\n" "{\n" "float texValue = texture(texID, srcCoordinatesVarying).r;\n" - "return vec4( step(mod(texValue, 8.0/256.0), 4.0/256.0), step(mod(texValue, 4.0/256.0), 2.0/256.0), step(mod(texValue, 2.0/256.0), 1.0/256.0), 1.0);\n" + "return vec4( step(4.0/256.0, mod(texValue, 8.0/256.0)), step(2.0/256.0, mod(texValue, 4.0/256.0)), step(1.0/256.0, mod(texValue, 2.0/256.0)), 1.0);\n" "}"; } diff --git a/Machines/Electron/Electron.hpp b/Machines/Electron/Electron.hpp index ac9b64b65..a172618ca 100644 --- a/Machines/Electron/Electron.hpp +++ b/Machines/Electron/Electron.hpp @@ -130,11 +130,14 @@ class Machine: public CPU6502::Processor { uint8_t _palette[16]; uint8_t _keyStates[14]; ROMSlot _activeRom; + uint8_t _screenMode; + uint16_t _screenModeBaseAddress; Outputs::CRT *_crt; int _frameCycles, _outputPosition; uint16_t _startScreenAddress, _startLineAddress, _currentScreenAddress; + int _currentOutputLine; uint8_t *_currentLine; inline void update_display();