68 lines
2.1 KiB
D
68 lines
2.1 KiB
D
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+ d6502/nmosbase.d
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+
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+ Copyright: 2007 Gerald Stocker
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+
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+ This file is part of Twoapple.
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+
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+ Twoapple is free software; you can redistribute it and/or modify
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+ it under the terms of the GNU General Public License as published by
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+ the Free Software Foundation; either version 2 of the License, or
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+ (at your option) any later version.
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+
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+ Twoapple is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+ GNU General Public License for more details.
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+
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+ You should have received a copy of the GNU General Public License
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+ along with Twoapple; if not, write to the Free Software
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+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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+/
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import d6502.cpu;
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class NmosBase : Cpu
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{
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this()
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{
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super();
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spuriousAddress = &badAddress;
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}
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static string RMW(string action)
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{
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return "poke(primaryAddress, (readVal = read(primaryAddress)));\n" ~
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"writeFinal(primaryAddress, flag.zero_ = flag.negative_ = " ~
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action ~ "(readVal));\n";
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}
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mixin(Opcode(mixin(Type2Address(
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"ASL", "Write", [0x06, 0x0E, 0x16, 0x1E])),
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RMW("shiftLeft")));
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mixin(Opcode(mixin(Type2Address(
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"LSR", "Write", [0x46, 0x4E, 0x56, 0x5E])),
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RMW("shiftRight")));
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mixin(Opcode(mixin(Type2Address(
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"ROL", "Write", [0x26, 0x2E, 0x36, 0x3E])),
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RMW("rotateLeft")));
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mixin(Opcode(mixin(Type2Address(
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"ROR", "Write", [0x66, 0x6E, 0x76, 0x7E])),
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RMW("rotateRight")));
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mixin(Opcode(mixin(Type2Address(
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"INC", "Write", [0xE6, 0xEE, 0xF6, 0xFE])),
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RMW("increment")));
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mixin(Opcode(mixin(Type2Address(
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"DEC", "Write", [0xC6, 0xCE, 0xD6, 0xDE])),
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RMW("decrement")));
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/* JMP ($$$$) */
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override void opcode6C()
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{
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ushort vector = readWordOperand();
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programCounter = readWord(vector,
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(vector & 0xFF00) | cast(ubyte)(vector + 1));
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version(CumulativeCycles) ticks(totalCycles);
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}
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}
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