apple2js/js/applesoft/decompiler.js

174 lines
3.9 KiB
JavaScript

export default function ApplesoftDump(mem)
{
var _mem = mem;
var LETTERS =
' ' +
' !"#$%&\'()*+,-./0123456789:;<=>?' +
'@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_' +
'`abcdefghijklmnopqrstuvwxyz{|}~ ';
var TOKENS = {
0x80: 'END',
0x81: 'FOR',
0x82: 'NEXT',
0x83: 'DATA',
0x84: 'INPUT',
0x85: 'DEL',
0x86: 'DIM',
0x87: 'READ',
0x88: 'GR',
0x89: 'TEXT',
0x8a: 'PR#',
0x8b: 'IN#',
0x8c: 'CALL',
0x8d: 'PLOT',
0x8e: 'HLIN',
0x8f: 'VLIN',
0x90: 'HGR2',
0x91: 'HGR',
0x92: 'HCOLOR=',
0x93: 'HPLOT',
0x94: 'DRAW',
0x95: 'XDRAW',
0x96: 'HTAB',
0x97: 'HOME',
0x98: 'ROT=',
0x99: 'SCALE=',
0x9a: 'SHLOAD',
0x9b: 'TRACE',
0x9c: 'NOTRACE',
0x9d: 'NORMAL',
0x9e: 'INVERSE',
0x9f: 'FLASH',
0xa0: 'COLOR=',
0xa1: 'POP=',
0xa2: 'VTAB',
0xa3: 'HIMEM:',
0xa4: 'LOMEM:',
0xa5: 'ONERR',
0xa6: 'RESUME',
0xa7: 'RECALL',
0xa8: 'STORE',
0xa9: 'SPEED=',
0xaa: 'LET',
0xab: 'GOTO',
0xac: 'RUN',
0xad: 'IF',
0xae: 'RESTORE',
0xaf: '&',
0xb0: 'GOSUB',
0xb1: 'RETURN',
0xb2: 'REM',
0xb3: 'STOP',
0xb4: 'ON',
0xb5: 'WAIT',
0xb6: 'LOAD',
0xb7: 'SAVE',
0xb8: 'DEF',
0xb9: 'POKE',
0xba: 'PRINT',
0xbb: 'CONT',
0xbc: 'LIST',
0xbd: 'CLEAR',
0xbe: 'GET',
0xbf: 'NEW',
0xc0: 'TAB(',
0xc1: 'TO',
0xc2: 'FN',
0xc3: 'SPC(',
0xc4: 'THEN',
0xc5: 'AT',
0xc6: 'NOT',
0xc7: 'STEP',
0xc8: '+',
0xc9: '-',
0xca: '*',
0xcb: '/',
0xcc: '^',
0xcd: 'AND',
0xce: 'OR',
0xcf: '>',
0xd0: '=',
0xd1: '<',
0xd2: 'SGN',
0xd3: 'INT',
0xd4: 'ABS',
0xd5: 'USR',
0xd6: 'FRE',
0xd7: 'SCRN(',
0xd8: 'PDL',
0xd9: 'POS',
0xda: 'SQR',
0xdb: 'RND',
0xdc: 'LOG',
0xdd: 'EXP',
0xde: 'COS',
0xdf: 'SIN',
0xe0: 'TAN',
0xe1: 'ATN',
0xe2: 'PEEK',
0xe3: 'LEN',
0xe4: 'STR$',
0xe5: 'VAL',
0xe6: 'ASC',
0xe7: 'CHR$',
0xe8: 'LEFT$',
0xe9: 'RIGHT$',
0xea: 'MID$'
};
function readByte(addr) {
var page = addr >> 8,
off = addr & 0xff;
return _mem.read(page, off);
}
function readWord(addr) {
var lsb, msb;
lsb = readByte(addr);
msb = readByte(addr + 1);
return (msb << 8) | lsb;
}
return {
toString: function () {
var str = '';
var start = readWord(0x67); // Start
var end = readWord(0xaf); // End of program
var addr = start;
do {
var line = '';
var next = readWord(addr);
addr += 2;
var lineno = readWord(addr);
addr += 2;
line += lineno;
line += ' ';
var val = false;
do {
if (addr < start || addr > end)
return str;
val = readByte(addr++);
if (val >= 0x80) {
line += ' ';
line += TOKENS[val];
line += ' ';
}
else
line += LETTERS[val];
} while (val);
line += '\n';
str += line;
addr = next;
} while (addr && addr >= start && addr < end);
return str;
}
};
}