public static void Stat(ushort unit)
{
Debug.Assert(unit < DiskIO.MaxUnits);
var u = DiskIO.unitTable[unit];
if (u == null || u.Fd == null && u.Data == null)
{
PSystem.IOError(9);
}
else
{
PSystem.IOError(0);
}
}
public static ushort SegmentSizePointer(ushort id) => PSystem.SegmentUnitPointer(id).Index(2);
public static ushort SegmentBlockPointer(ushort id) => PSystem.SegmentUnitPointer(id).Index(1);
public static void Process(ushort entryPoint)
{
var op = (DecimalOps)Stack.Pop();
switch (op)
{
case DecimalOps.Adjust:
{
var newLen = Stack.Pop();
var len = Stack.Pop() & 0xFF;
var sign = Stack.Pop();
if (len < newLen)
{
while (len++ < newLen)
{
Stack.Push(0);
}
}
else
{
while (len-- > newLen)
{
Stack.Pop();
}
}
Stack.Push(sign);
}
break;
case DecimalOps.Add:
{
LongInteger.Pop(out var arg2);
LongInteger.Pop(out var arg1);
LongInteger.Add(ref arg1, ref arg2, out var result);
LongInteger.Push(ref result);
}
break;
case DecimalOps.Subtract:
{
LongInteger.Pop(out var arg2);
LongInteger.Pop(out var arg1);
LongInteger.Subtract(ref arg1, ref arg2, out var result);
LongInteger.Push(ref result);
}
break;
case DecimalOps.Negate:
{
var len = Stack.Pop();
var sign = Stack.Pop() == 0 ? 1 : 0;
Stack.Push((ushort)(sign != 0 ? 0xFF : 0));
Stack.Push(len);
}
break;
case DecimalOps.Multiply:
{
LongInteger.Pop(out var arg2);
LongInteger.Pop(out var arg1);
LongInteger.Multiply(ref arg1, ref arg2, out var result);
LongInteger.Push(ref result);
}
break;
case DecimalOps.Divide:
{
LongInteger.Pop(out var arg2);
LongInteger.Pop(out var arg1);
if (!LongInteger.Divide(ref arg1, ref arg2, out var result))
{
throw new ExecutionException(ExecutionErrorCode.DivideByZero);
}
LongInteger.Push(ref result);
}
break;
case DecimalOps.Str:
{
Stack.Pop();
var strAddress = Stack.Pop();
var intLen = Stack.Pop();
var sign = Stack.Pop();
short idx = 0;
if (sign != 0)
{
Memory.WriteByte(strAddress, ++idx, (byte)'-');
}
var suppress = true;
while (intLen-- > 0)
{
var w = Stack.Pop();
for (var i = 0; i < 4; i++)
{
var digit = (byte)(w >> 4 * i & 0xF);
if (suppress && digit <= 0)
{
continue;
}
Memory.WriteByte(strAddress, ++idx, (byte)(digit + (byte)'0'));
suppress = false;
}
}
if (suppress)
{
Memory.WriteByte(strAddress, ++idx, (byte)'0');
}
Memory.WriteByte(strAddress, 0, (byte)idx);
}
break;
case DecimalOps.Compare:
{
var cmp = Stack.Pop();
LongInteger.Pop(out var arg2);
LongInteger.Pop(out var arg1);
var result = LongInteger.Compare(ref arg1, ref arg2);
switch (cmp)
{
case 8: // <
Stack.Push(PSystem.Boolean(result < 0));
break;
case 9: // <=
Stack.Push(PSystem.Boolean(result <= 0));
break;
case 10: // >=
Stack.Push(PSystem.Boolean(result >= 0));
break;
case 11: // >
Stack.Push(PSystem.Boolean(result > 0));
break;
case 12: // !=
Stack.Push(PSystem.Boolean(result != 0));
break;
case 13: // ==
Stack.Push(PSystem.Boolean(result == 0));
break;
default:
throw new ExecutionException(ExecutionErrorCode.UnimplementedInstruction);
}
}
break;
case DecimalOps.ConvertTos:
{
var val = Stack.PopInteger();
var sign = val < 0;
if (!sign)
{
val = (short)-val;
}
for (var i = 0; i < 2; i++)
{
ushort w = 0;
for (var j = 0; j < 4; j++)
{
w = (ushort)((w << 4) - val % 10);
val /= 10;
}
Stack.Push(w);
}
Stack.Push((ushort)(sign ? 0xFF : 0));
Stack.Push(3);
}
break;
case DecimalOps.Truncate:
{
LongInteger.Pop(out var arg1);
var result = arg1.Value.Aggregate <byte, short>(0, (current, t) => (short)(current * 10 - t));
if (arg1.Sign == BcSign.Minus)
{
Stack.Push(result);
}
else
{
Stack.Push((short)-result);
}
}
break;
//case DecimalOps.ConvertTosM1:
default:
throw new ExecutionException(ExecutionErrorCode.UnimplementedInstruction);
}
}
public static void Read(ushort unit, ushort address, short addressOffset, ushort len, ushort blockNo)
{
var offset = blockNo * 512u;
var track = blockNo / 8;
var sector = (blockNo & 7) * 2;
Debug.Assert(unit < DiskIO.MaxUnits);
var u = DiskIO.unitTable[unit];
if (u == null || u.Fd == null && u.Data == null)
{
PSystem.IOError(9);
return;
}
if (offset + len > u.Size)
{
PSystem.IOError(64);
return;
}
while (len != 0)
{
var size = 256;
var sec = sector;
if (len < size)
{
size = len;
}
//if (u.Translate != null)
// sec = u.Translate[sector];
int i;
if (u.Data != null)
{
for (i = 0; i < size; i++)
{
Memory.WriteByte
(
address,
(short)(addressOffset + i),
u.Data[(track * 16 + sec) * 256 + i]
);
}
}
else if (u.Fd != null)
{
var buf = new byte[256];
bool failed;
try
{
u.Fd.Seek((track * 16 + sec) * 256, SeekOrigin.Begin);
failed = u.Fd.Read(buf, 0, size) < size;
}
catch
{
failed = true;
}
if (failed)
{
PSystem.IOError(64);
return;
}
for (i = 0; i < size; i++)
{
Memory.WriteByte(address, (short)(addressOffset + i), buf[i]);
}
}
addressOffset += (short)size;
len -= (ushort)size;
sector++;
if (sector < 16)
{
continue;
}
track++;
sector = 0;
}
PSystem.IOError(0);
}
public static void Clear(ushort unit)
{
Debug.Assert(unit < DiskIO.MaxUnits);
PSystem.IOError(0);
}
