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apple II language card

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This commit is contained in:
Steven Hugg 2017-01-05 14:49:48 -05:00
parent 346bab90fd
commit 5e8cf0f71f
1 changed files with 102 additions and 16 deletions
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118
src/platform/apple2.js
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@ -12,13 +12,20 @@ var Apple2Platform = function(mainElement) {
var self = this;
var cpuFrequency = 1023000;
var cpuCyclesPerLine = 65;
var cpu, ram, rom, bus;
var cpu, ram, bus;
var video, ap2disp, audio, timer;
var grdirty = [];
var grdirty = new Array(0xc000 >> 7);
var grswitch = GR_TXMODE;
var kbdlatch = 0;
var soundstate = 0;
var PGM_BASE = 0x6000;
var PGM_BASE = 0x6000; // where to JMP after pr#6
// language card switches
var auxRAMselected = false;
var auxRAMbank = 1;
var writeinhibit = true;
// value to add when reading & writing each of these banks
// bank 1 is E000-FFFF, bank 2 is D000-DFFF
var bank2rdoffset=0, bank2wroffset=0;
this.getPresets = function() {
return APPLE2_PRESETS;
@ -30,16 +37,25 @@ var Apple2Platform = function(mainElement) {
this.start = function() {
cpu = new jt.M6502();
ram = new RAM(0xc000);
rom = new lzgmini().decode(APPLEIIGO_LZG).slice(0,12288);
ram = new RAM(0x13000); // 64K + 16K LC RAM - 4K hardware
// ROM
var rom = new lzgmini().decode(APPLEIIGO_LZG).slice(0,0x3000);
ram.mem.set(rom, 0xd000);
// bus
bus = {
read: function(address) {
address &= 0xffff;
if (address >= 0xd000 && address <= 0xffff) {
return rom[address - 0xd000];
} else if (address < 0xc000) {
if (address < 0xc000) {
return ram.mem[address];
} else if (address >= 0xd000) {
//return rom[address - 0xd000] & 0xff;
//console.log(hex(address), rom[address-0xd000], ram.mem[address]);
if (!auxRAMselected)
return rom[address - 0xd000];
else if (address >= 0xe000)
return ram.mem[address];
else
return ram.mem[address + bank2rdoffset];
} else if (address < 0xc100) {
var slot = (address >> 4) & 0x0f;
switch (slot)
@ -81,9 +97,9 @@ var Apple2Platform = function(mainElement) {
if (address == 0xc070)
return noise() | 0x80;
case 8:
return doLanguageCardIO(address, value);
return 0; // TODO doLanguageCardIO(address, value);
case 9: case 10: case 11: case 12: case 13: case 14: case 15:
return slots[slot-8].doIO(address, value);
return noise(); // return slots[slot-8].doIO(address, value);
}
} else {
switch (address) {
@ -98,11 +114,17 @@ var Apple2Platform = function(mainElement) {
},
write: function(address, val) {
address &= 0xffff;
val &= 0xff;
if (address < 0xc000) {
ram.mem[address] = val;
grdirty[address>>7] = 1;
} else if (address < 0xc100) {
this.read(address); // strobe address
this.read(address); // strobe address, discard result
} else if (address >= 0xd000 && !writeinhibit) {
if (address >= 0xe000)
ram.mem[address] = val;
else
ram.mem[address + bank2wroffset] = val;
}
}
};
@ -137,15 +159,79 @@ var Apple2Platform = function(mainElement) {
});
}
function doLanguageCardIO(address, value)
{
switch (address & 0x0f) {
// Select aux RAM bank 2, write protected.
case 0x0:
case 0x4:
auxRAMselected = true;
auxRAMbank = 2;
writeinhibit = true;
break;
// Select ROM, write enable aux RAM bank 2.
case 0x1:
case 0x5:
auxRAMselected = false;
auxRAMbank = 2;
writeinhibit = false;
break;
// Select ROM, write protect aux RAM (either bank).
case 0x2:
case 0x6:
case 0xA:
case 0xE:
auxRAMselected = false;
writeinhibit = true;
break;
// Select aux RAM bank 2, write enabled.
case 0x3:
case 0x7:
auxRAMselected = true;
auxRAMbank = 2;
writeinhibit = false;
break;
// Select aux RAM bank 1, write protected.
case 0x8:
case 0xC:
auxRAMselected = true;
auxRAMbank = 1;
writeinhibit = true;
break;
// Select ROM, write enable aux RAM bank 1.
case 0x9:
case 0xD:
auxRAMselected = false;
auxRAMbank = 1;
writeinhibit = false;
break;
// Select aux RAM bank 1, write enabled.
case 0xB:
case 0xF:
auxRAMselected = true;
auxRAMbank = 1;
writeinhibit = false;
break;
}
// reset language card constants
if (auxRAMbank == 2)
bank2rdoffset = -0x1000; // map 0xd000-0xdfff -> 0xc000-0xcfff
else
bank2rdoffset = 0x3000; // map 0xd000-0xdfff -> 0x10000-0x10fff
if (auxRAMbank == 2)
bank2wroffset = -0x1000; // map 0xd000-0xdfff -> 0xc000-0xcfff
else
bank2wroffset = 0x3000; // map 0xd000-0xdfff -> 0x10000-0x10fff
return noise();
}
this.getOpcodeMetadata = function(opcode, offset) {
return Javatari.getOpcodeMetadata(opcode, offset); // TODO
}
this.loadROM = function(title, data) {
this.reset();
for (var i=0; i<data.length; i++) {
ram.mem[i+PGM_BASE] = data[i];
}
ram.mem.set(data, PGM_BASE);
/*
if(data.length != 0x3000) {
throw "ROM length must be == 0x3000";
@ -272,7 +358,7 @@ var Apple2Display = function(pixels, apple) {
var PIXELOFF = 0xff000000;
var oldgrmode = -1;
var textbuf = [];
var textbuf = new Array(40*24);
var flashInterval = 500;
@ -326,7 +412,7 @@ var Apple2Display = function(pixels, apple) {
* for odd and even addresses (2) and each byte displays 7 pixels.
*/
{
colors_lut = []; //new int[256*4*2*7];
colors_lut = new Array(256*4*2*7);
var i,j;
var c1,c2,c3 = 15;
var base = 0;