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Minor vga changes

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copy 2017-03-04 15:53:31 -05:00
parent 7a1de12ca5
commit 8266de747f
1 changed files with 51 additions and 6 deletions
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57
src/vga.js
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@ -73,6 +73,13 @@ function VGAScreen(cpu, bus, vga_memory_size)
*/
this.start_address = 0;
this.crtc = new Uint8Array(0x19);
/**
* @type {number}
*/
this.previous_start_address = 0;
/** @type {boolean} */
this.graphical_mode_is_linear = true;
@ -195,6 +202,9 @@ function VGAScreen(cpu, bus, vga_memory_size)
io.register_write_consecutive(0x3D4, this, this.port3D4_write, this.port3D5_write);
io.register_read(0x3D5, this, this.port3D5_read);
io.register_read(0x3D4, this, function() { dbg_log("3D4 read", LOG_VGA); return 0; });
io.register_read(0x3CA, this, function() { dbg_log("3CA read", LOG_VGA); return 0; });
io.register_read(0x3DA, this, this.port3DA_read);
@ -633,6 +643,7 @@ VGAScreen.prototype.vga_memory_write_text_mode = function(addr, value)
chr,
color;
// XXX: Should handle 16 bit write if possible
if(addr & 1)
{
color = value;
@ -761,6 +772,9 @@ VGAScreen.prototype.set_video_mode = function(mode)
switch(mode)
{
case 0x66:
this.set_size_text(110, 46);
break;
case 0x03:
this.set_size_text(this.text_mode_width, 25);
break;
@ -982,14 +996,14 @@ VGAScreen.prototype.port3CF_write = function(value)
break;
case 5:
this.planar_mode = value;
//dbg_log("planar mode: " + h(value), LOG_VGA);
dbg_log("planar mode: " + h(value), LOG_VGA);
break;
case 8:
this.planar_bitmap = value;
//dbg_log("planar bitmap: " + h(value), LOG_VGA);
dbg_log("planar bitmap: " + h(value), LOG_VGA);
break;
default:
//dbg_log("3CF / graphics write " + h(this.graphics_index) + ": " + h(value), LOG_VGA);
dbg_log("3CF / graphics write " + h(this.graphics_index) + ": " + h(value), LOG_VGA);
}
};
@ -1043,12 +1057,24 @@ VGAScreen.prototype.port3D5_write = function(value)
this.update_cursor_scanline();
break;
case 0xC:
this.previous_start_address = this.start_address;
this.start_address = this.start_address & 0xff | value << 8;
this.complete_redraw();
break;
case 0xD:
this.start_address = this.start_address & 0xff00 | value;
this.complete_redraw();
var delta = this.start_address - this.previous_start_address;
if(delta)
{
//if(!this.graphical_mode && delta % this.text_mode_width === 0)
//{
// this.bus.send("screen-text-scroll", delta / this.text_mode_width);
//}
//else
{
this.complete_redraw();
}
}
dbg_log("start addr: " + h(this.start_address, 4), LOG_VGA);
break;
case 0xE:
@ -1063,6 +1089,10 @@ VGAScreen.prototype.port3D5_write = function(value)
this.offset_register = value;
break;
default:
if(this.index_crtc < this.crtc.length)
{
this.crtc[this.index_crtc] = value;
}
dbg_log("3D5 / CRTC write " + h(this.index_crtc) + ": " + h(value), LOG_VGA);
}
@ -1086,12 +1116,23 @@ VGAScreen.prototype.port3D5_read = function()
return this.cursor_address >> 8;
case 0xF:
return this.cursor_address & 0xFF;
case 0x1:
return 80; // cols
case 0x12:
return 50; // rows
case 0x13:
return this.offset_register;
}
dbg_log("3D5 read " + h(this.index_crtc), LOG_VGA);
return 0;
if(this.index_crtc < this.crtc.length)
{
return this.crtc[this.index_crtc];
}
else
{
return 0;
}
};
VGAScreen.prototype.port3DA_read = function()
@ -1107,7 +1148,11 @@ VGAScreen.prototype.switch_video_mode = function(mar)
// Cheap way to figure this out, using the Miscellaneous Output Register
// See: http://wiki.osdev.org/VGA_Hardware#List_of_register_settings
if(mar === 0x67)
if(mar === 0x66)
{
this.set_video_mode(0x66);
}
else if(mar === 0x67)
{
this.set_video_mode(0x3);
}