apple2js/js/cards/ramfactor.js
Will Scullin afc5280ac2
Flesh out some state stuff (#59)
Get save and restore state limping along to nearly as well as before I refactored and broke everything.
2021-02-27 19:17:36 -08:00

157 lines
4.1 KiB
JavaScript

/* Copyright 2010-2019 Will Scullin <scullin@scullinsteel.com>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation. No representations are made about the suitability of this
* software for any purpose. It is provided "as is" without express or
* implied warranty.
*/
import { allocMem, debug } from '../util';
import { rom } from '../roms/cards/ramfactor';
export default function RAMFactor(io, size) {
var mem = [];
var _firmware = 0;
var _ramlo = 0;
var _rammid = 0;
var _ramhi = 0;
var _loc = 0;
var LOC = {
// Disk II Stuff
RAMLO: 0x80,
RAMMID: 0x81,
RAMHI: 0x82,
RAMDATA: 0x83,
_RAMLO: 0x84,
_RAMMID: 0x85,
_RAMHI: 0x86,
_RAMDATA: 0x87,
BANK: 0x8F
};
function _init() {
debug('RAMFactor card');
mem = allocMem(size);
for (var off = 0; off < size; off++) {
mem[off] = 0;
}
}
function _sethi(val) {
_ramhi = (val & 0xff);
}
function _setmid(val) {
if (((_rammid & 0x80) !== 0) && ((val & 0x80) === 0)) {
_sethi(_ramhi + 1);
}
_rammid = (val & 0xff);
}
function _setlo(val) {
if (((_ramlo & 0x80) !== 0) && ((val & 0x80) === 0)) {
_setmid(_rammid + 1);
}
_ramlo = (val & 0xff);
}
function _access(off, val) {
var result = 0;
switch (off & 0x8f) {
case LOC.RAMLO:
case LOC._RAMLO:
if (val !== undefined) {
_setlo(val);
} else {
result = _ramlo;
}
break;
case LOC.RAMMID:
case LOC._RAMMID:
if (val !== undefined) {
_setmid(val);
} else {
result = _rammid;
}
break;
case LOC.RAMHI:
case LOC._RAMHI:
if (val !== undefined) {
_sethi(val);
} else {
result = _ramhi;
result |= 0xf0;
}
break;
case LOC.RAMDATA:
case LOC._RAMDATA:
if (val !== undefined) {
mem[_loc % mem.length] = val;
} else {
result = mem[_loc % mem.length];
}
_setlo(_ramlo + 1);
break;
case LOC.BANK:
if (val !== undefined) {
_firmware = val & 0x01;
} else {
result = _firmware;
}
break;
default:
break;
}
_loc = (_ramhi << 16) | (_rammid << 8) | (_ramlo);
/*
if (val === undefined) {
debug("Read: " + toHex(result) + " from " + toHex(off) + " (loc = " + _loc + ")");
} else {
debug("Wrote: " + toHex(val) + " to " + toHex(off) + " (loc = " + _loc + ")");
}
*/
return result;
}
_init();
return {
ioSwitch: function (off, val) {
return _access(off, val);
},
read: function ramfactor_read(page, off) {
return rom[_firmware << 12 | (page - 0xC0) << 8 | off];
},
write: function ramfactor_write() {},
reset: function ramfactor_reset() {
_firmware = 0;
},
getState: function() {
return {
loc: _loc,
firmware: _firmware,
mem: new Uint8Array(mem)
};
},
setState: function(state) {
_loc = state.loc;
_firmware = state.firmware;
mem = new Uint8Array(state.mem);
_ramhi = (_loc >> 16) & 0xff;
_rammid = (_loc >> 8) & 0xff;
_ramlo = (_loc) & 0xff;
}
};
}