58 lines
1.7 KiB
JavaScript
58 lines
1.7 KiB
JavaScript
/* -*- mode: JavaScript; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/* Copyright 2010-2019Will 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 { base64_decode, base64_encode } from './base64';
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import { allocMemPages } from './util';
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export default function RAM(sp, ep) {
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var mem;
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var start_page = sp;
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var end_page = ep;
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mem = allocMemPages(ep - sp + 1);
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for (var page = 0; page <= ep; page++) {
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for (var off = 0; off < 0x100; off++) {
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mem[page * 0x100 + off] = 0; // Math.floor(Math.random()*256);
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}
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}
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return {
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start: function() {
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return start_page;
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},
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end: function() {
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return end_page;
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},
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read: function(page, off) {
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return mem[(page - start_page) * 0x100 + off];
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},
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write: function(page, off, val) {
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mem[(page - start_page) * 0x100 + off] = val;
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},
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getState: function() {
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return {
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start: start_page,
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end: end_page,
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mem: base64_encode(mem)
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};
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},
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setState: function(state) {
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start_page = state.start;
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end_page = state.end;
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mem = base64_decode(state.mem);
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}
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};
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}
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