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mirror of https://github.com/livingcomputermuseum/sImlac.git synced 2026-01-13 15:27:40 +00:00
livingcomputermuseum.sImlac/imlac/DisplayProcessor.cs

543 lines
17 KiB
C#

/*
This file is part of sImlac.
sImlac is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
sImlac is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with sImlac. If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using System.Collections.Generic;
using imlac.IO;
using imlac.Debugger;
namespace imlac
{
public enum DisplayProcessorMode
{
Indeterminate,
Processor,
Increment,
MediumVector,
CompactAddressing,
}
public enum ImmediateHalf
{
First,
Second
}
/// <summary>
/// DisplayProcessorBase is an abstract class providing the logic sharable between the
/// PDS-1 and PDS-4's display processors.
/// </summary>
public abstract class DisplayProcessorBase : IIOTDevice
{
public DisplayProcessorBase(ImlacSystem system)
{
_system = system;
_mem = _system.Memory;
_dtStack = new Stack<ushort>(8);
InitializeCache();
}
public virtual void Reset()
{
_state = ProcessorState.Halted;
_halted = true;
_mode = DisplayProcessorMode.Processor;
_immediateHalf = ImmediateHalf.First;
_immediateWord = 0;
_pc = 0;
_dpcEntry = 0;
_block = 0;
_dtStack.Clear();
_x = 0;
_y = 0;
_scale = 1.0f;
_dadr = false;
_system.Display.MoveAbsolute(0, 0, DrawingMode.Off);
_clocks = 0;
_frameLatch = false;
}
public ushort PC
{
get { return _pc; }
set
{
_pc = value;
// block is set whenever DPC is set by the main processor
// only on non-MIT modded systems
if (!Configuration.MITMode)
{
_block = (ushort)(value & 0x3000);
}
if (Trace.TraceOn) Trace.Log(LogType.DisplayProcessor, "DPC set to {0} (block {1})", Helpers.ToOctal(_pc), Helpers.ToOctal(_block));
}
}
public ProcessorState State
{
get { return _state; }
set
{
_state = value;
if (_state == ProcessorState.Halted)
{
if (Trace.TraceOn) Trace.Log(LogType.DisplayProcessor, "Display processor halted.");
}
else
{
if (Trace.TraceOn) Trace.Log(LogType.DisplayProcessor, "Display processor started.");
}
}
}
public bool DisplayHalted
{
get { return _halted; }
}
public DisplayProcessorMode Mode
{
get { return _mode; }
}
public ImmediateHalf Half
{
get { return _immediateHalf; }
}
public ushort DT
{
get
{
if (_dtStack.Count > 0)
{
return _dtStack.Peek();
}
else
{
return 0;
}
}
}
public bool FrameLatch
{
get { return _frameLatch; }
}
public int X
{
get { return _x; }
set
{
_x = value & 0x7ff;
}
}
public int Y
{
get { return _y; }
set
{
_y = value & 0x7ff;
}
}
/// <summary>
/// Tracks the entry point to the display processor's current program
/// program.
/// </summary>
public ushort DPCEntry
{
get { return _dpcEntry; }
}
/// <summary>
/// Set whenever a display drawing or movement operation has completed.
/// Reset on read.
/// </summary>
public bool DisplayDrawLatch
{
get
{
bool latch = _displayDrawLatch;
_displayDrawLatch = false;
return latch;
}
}
//
// Push and Pop are used on the PDS-4 to allow the main processor control of the
// DPC stack. (Called the MDS on the PDS-4)
//
public void Push()
{
_dtStack.Push((ushort)(_pc + 1));
if (Trace.TraceOn) Trace.Log(LogType.DisplayProcessor, "DT stack push {0}, depth is now {1}", Helpers.ToOctal((ushort)(_pc + 1)), _dtStack.Count);
}
public void Pop()
{
if (_dtStack.Count > 0)
{
_pc = _dtStack.Pop();
if (Trace.TraceOn) Trace.Log(LogType.DisplayProcessor, "DT stack pop {0}, depth is now {1}", Helpers.ToOctal(_pc), _dtStack.Count);
}
else
{
if (Trace.TraceOn) Trace.Log(LogType.DisplayProcessor, "DT stack empty on pop! Leaving DPC undisturbed at {0}", Helpers.ToOctal(_pc));
}
}
public virtual void StartProcessor()
{
State = ProcessorState.Running;
// MIT DADR bit gets reset when display is started.
_dadr = false;
_halted = false;
}
public virtual void HaltProcessor()
{
State = ProcessorState.Halted;
_halted = true;
}
public abstract void InitializeCache();
public abstract void InvalidateCache(ushort address);
public abstract string Disassemble(ushort address, DisplayProcessorMode mode, out int length);
public abstract void Clock();
public abstract int[] GetHandledIOTs();
public abstract void ExecuteIOT(int iotCode);
protected void MoveAbsolute(int x, int y, DrawingMode mode)
{
_displayDrawLatch = true;
_system.Display.MoveAbsolute(x, y, mode);
}
protected void DrawPoint(int x, int y)
{
_displayDrawLatch = true;
_system.Display.DrawPoint(x, y);
}
protected int _x;
protected int _y;
protected float _scale;
protected ushort _pc;
protected ushort _block;
protected Stack<ushort> _dtStack;
// Used for debugging purposes:
protected ushort _dpcEntry;
protected bool _displayDrawLatch;
// MIT DADR (display addressing) flag.
protected bool _dadr;
protected ushort _immediateWord;
protected ImmediateHalf _immediateHalf;
protected int _clocks;
protected bool _frameLatch;
protected ProcessorState _state;
protected bool _halted; // The halted flag is set to indicate that the processor
// has previously halted itself and is independent of the
// current state of the processor.
protected DisplayProcessorMode _mode;
protected ImlacSystem _system;
protected Memory _mem;
/// <summary>
/// All display Opcode mnemonics, shared across implementations
/// of DisplayInstructionBase, unfortunately.
/// </summary>
protected enum DisplayOpcode
{
Invalid, // Set when an instruction could not be decoded.
// Basic instructions
DLXA, // Load X Accumulator
DLYA, // Load Y Accumulator
DEIM, // Enter Immediate Mode
DJMS, // Jump to subroutine
DJMP, // Jump to address
DHLT, // Halt display
DNOP, // No op
DSTS, // Set scale
DSTB, // Set block
DDSP, // Display intensification
DIXM, // Display increment X MSB
DIYM, // Display increment Y MSB
DDXM, // Display decrement X MSB
DDYM, // Display decrement Y MSB
DRJM, // Return jump
DHVC, // Display HV Sync
DLVH, // Long vector
DOPR, // Generic Display OPR microinstruction
// Optional extended instructions
SGR1,
ASG1,
VIC1,
MCI1,
STI1,
LPA1,
// PDS-4 only instructions
DMVM, // Medium Vector Mode
DCAM, // Compact Addressing Mode
DBLI, // Blinking
DFXY, // Fast X/Y Mode
DVIC, // Variable Intensity
DASG, // Automatic Increment and Intensify
DROR, // Character Rotation/Reflection
DARX, // Add Relative X
DARY, // Add Relative Y
}
protected abstract class DisplayInstructionBase
{
public DisplayInstructionBase(ushort word, ushort address, DisplayProcessorMode mode)
{
_usageMode = mode;
_word = word;
_address = address;
Decode();
}
public DisplayOpcode Opcode
{
get { return _opcode; }
}
public ushort Data
{
get { return _data; }
}
/// <summary>
/// Set when the instruction is actually executed by the display processor.
/// Used to aid in disassembly (since it provides the context needed to determine what type of
/// processor instruction it is)
/// </summary>
public DisplayProcessorMode UsageMode
{
get { return _usageMode; }
set { _usageMode = value; }
}
/// <summary>
/// Implementors provide a disassembly string representing this instruction.
/// </summary>
/// <param name="mode"></param>
/// <returns></returns>
public abstract string Disassemble(DisplayProcessorMode mode, Memory mem, out int length);
/// <summary>
/// Implemented to provide decoding of this instruction word.
/// </summary>
protected abstract void Decode();
protected string DisassembleIncrement()
{
return DisassembleIncrementHalf(ImmediateHalf.First) + " | " + DisassembleIncrementHalf(ImmediateHalf.Second);
}
private string DisassembleIncrementHalf(ImmediateHalf half)
{
string ret = string.Empty;
int halfWord = half == ImmediateHalf.First ? (_word & 0xff00) >> 8 : (_word & 0xff);
// translate the half word to vector movements or escapes
// special case for "Enter Immediate mode" halfword (030) in first half.
if (half == ImmediateHalf.First && halfWord == 0x30)
{
ret += "E";
}
else if ((halfWord & 0x80) == 0)
{
if ((halfWord & 0x10) != 0)
{
ret += "IX ";
}
if ((halfWord & 0x08) != 0)
{
ret += "ZX ";
}
if (half == ImmediateHalf.Second &&
(halfWord & 0x04) != 0)
{
ret += "E PPM ";
}
if ((halfWord & 0x02) != 0)
{
ret += "IY ";
}
if ((halfWord & 0x01) != 0)
{
ret += "ZY ";
}
if ((halfWord & 0x40) != 0)
{
if ((halfWord & 0x20) != 0)
{
// escape and return
ret += "F RJM";
}
else
{
// Escape
ret += "F";
}
}
}
else
{
int xSign = ((halfWord & 0x20) == 0) ? 1 : -1;
int xMag = (int)(((halfWord & 0x18) >> 3));
int ySign = (int)(((halfWord & 0x04) == 0) ? 1 : -1);
int yMag = (int)((halfWord & 0x03));
ret += String.Format("{0},{1} {2}", xMag * xSign, yMag * ySign, (halfWord & 0x40) == 0 ? "OFF" : "ON");
}
return ret;
}
protected string DisassembleProcessor(Memory mem, out int length)
{
length = 1;
string ret = String.Empty;
if (_opcode == DisplayOpcode.DOPR)
{
string[] codes = { "INV0 ", "INV1 ", "INV2 ", "INV3 ", "DDSP ", "DRJM ", "DDYM ", "DDXM ", "DIYM ", "DIXM ", "DHVC ", "DHLT " };
for (int i = 4; i < 11; i++)
{
if ((_data & (0x01) << i) != 0)
{
if (!string.IsNullOrEmpty(ret))
{
ret += ",";
}
ret += codes[i];
}
}
// display halt if bit 4 is unset
if ((_data & 0x800) == 0)
{
ret += " DHLT ";
}
// F/C ops:
int f = (_data & 0xc) >> 2;
int c = _data & 0x3;
switch (f)
{
case 0x0:
// nothing
if (c == 1)
{
ret += String.Format("DADR");
}
break;
case 0x1:
ret += String.Format("DSTS {0}", c);
break;
case 0x2:
ret += String.Format("DSTB {0}", c);
break;
case 0x3:
ret += String.Format("DLPN {0}", c);
break;
}
}
else
{
switch (_opcode)
{
case DisplayOpcode.DEIM:
ret = String.Format("DEIM | {0} {1}",
DisassembleIncrementHalf(ImmediateHalf.Second),
(_word & 0xff00) == 0x3800 ? "Enter PPM" : String.Empty);
break;
case DisplayOpcode.DLXA:
ret = String.Format("DLXA {0} ({1})", Helpers.ToOctal(_data), _data);
break;
case DisplayOpcode.DLYA:
ret = String.Format("DLXA {0} ({1})", Helpers.ToOctal(_data), _data);
break;
case DisplayOpcode.DJMS:
ret = String.Format("DJMS {0}", Helpers.ToOctal(_data));
break;
case DisplayOpcode.DJMP:
ret = String.Format("DJMP {0}", Helpers.ToOctal(_data));
break;
default:
ret = DisassembleExtended(mem, out length);
break;
}
}
return ret;
}
protected abstract string DisassembleExtended(Memory mem, out int length);
protected DisplayOpcode _opcode;
protected ushort _data;
protected DisplayProcessorMode _usageMode;
protected ushort _word;
protected ushort _address;
}
}
}