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120 lines
3.1 KiB
JavaScript
120 lines
3.1 KiB
JavaScript
/* Copyright 2010-2019 Will Scullin <scullin@scullinsteel.com>
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*
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* Permission to use, copy, modify, distribute, and sell this software and its
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* documentation for any purpose is hereby granted without fee, provided that
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* the above copyright notice appear in all copies and that both that
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* copyright notice and this permission notice appear in supporting
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* documentation. No representations are made about the suitability of this
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* software for any purpose. It is provided "as is" without express or
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* implied warranty.
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*/
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import { debug } from '../util';
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export default function NoSlotClock(rom)
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{
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var PATTERN = [
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0xC5, 0x3A, 0xA3, 0x5C, 0xC5, 0x3A, 0xA3, 0x5C
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];
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var A0 = 0x01;
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var A2 = 0x04;
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function _init() {
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debug('NoSlotClock');
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}
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var _bits = [];
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var _pattern = new Array(64);
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var _patternIdx = 0;
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function _patternMatch() {
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for (var idx = 0; idx < 8; idx++) {
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var byte = 0;
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for (var jdx = 0; jdx < 8; jdx++) {
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byte >>= 1;
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byte |= _pattern.shift() ? 0x80 : 0x00;
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}
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if (byte !== PATTERN[idx]) {
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return false;
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}
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}
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return true;
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}
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function _calcBits() {
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function shift(val) {
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for (var idx = 0; idx < 4; idx++) {
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_bits.push(val & 0x08 ? 0x01 : 0x00);
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val <<= 1;
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}
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}
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function shiftBCD(val) {
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shift(parseInt(val / 10, 10));
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shift(parseInt(val % 10, 10));
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}
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var now = new Date();
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var year = now.getFullYear() % 100;
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var day = now.getDate();
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var weekday = now.getDay() + 1;
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var month = now.getMonth() + 1;
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var hour = now.getHours();
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var minutes = now.getMinutes();
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var seconds = now.getSeconds();
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var hundredths = (now.getMilliseconds() / 10);
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_bits = [];
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shiftBCD(year);
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shiftBCD(month);
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shiftBCD(day);
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shiftBCD(weekday);
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shiftBCD(hour);
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shiftBCD(minutes);
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shiftBCD(seconds);
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shiftBCD(hundredths);
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}
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_init();
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function _access(off) {
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if (off & A2) {
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_patternIdx = 0;
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} else {
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var bit = off & A0;
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_pattern[_patternIdx++] = bit;
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if (_patternIdx === 64) {
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if (_patternMatch()) {
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_calcBits();
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}
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_patternIdx = 0;
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}
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}
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}
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return {
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start: function nsc_start() {
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return rom.nsc_start();
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},
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end: function nsc_end() {
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return rom.nsc_end();
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},
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read: function nsc_read(page, off) {
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if (_bits.length > 0) {
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var bit = _bits.pop();
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return bit;
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} else {
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_access(off);
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}
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return rom.read(page, off);
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},
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write: function nsc_write(page, off, val) {
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_access(off);
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rom.write(page, off, val);
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},
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};
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}
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