static ushort ReadFile(ushort seg, string fn)
{
Console.Write("Reading ");
Console.Write(fn);
Console.Write(' ');
ushort pos = FDC.SearchFile(fn);
if (pos == 0)
{
Console.WriteLine();
Console.WriteLine("ERROR: can not find!");
return(0);
}
new Inline("push es");
Registers.ES = seg;
ushort ret = 0;
for (;;)
{
FDC.ReadSectors((ushort)(pos + 31), 1, 0);
ret++;
Registers.ES += 0x20;
Console.Write(".");
pos = FDC.GetFAT(pos);
if (pos == 0x0fff)
{
break;
}
}
new Inline("pop es");
Console.WriteLine();
return(ret);
}
/// <summary>
/// Read sectors.
/// </summary>
/// <param name="pos">start sector</param>
/// <param name="count">number of sectors to read</param>
/// <param name="ptr">es:bx = read address (es = 64kb align, bx = 512 bytes align)</param>
public static void ReadSectors(ushort pos, ushort count, ushort ptr)
{
new Inline("push es");
while (count > 0)
{
ushort ptr2 = (ushort)(0 - (short)ptr);
ptr2--;
ptr2 >>= 9;
ptr2++;
if (ptr2 > count)
{
ptr2 = count;
}
while (ptr2 > 0)
{
byte track = (byte)(pos / 0x24);
byte track_rem = (byte)(pos % 0x24);
byte head = (byte)(track_rem / 0x12);
byte sector = (byte)(track_rem % 0x12);
byte n = (byte)(0x12 - sector);
if (n > ptr2)
{
n = (byte)ptr2;
}
if (!FDC.Read(n, ptr, track, (byte)(sector + 1), head, 0))
{
FDC.Reset(0);
continue;
}
ptr += (ushort)(n << 9);
pos += n;
count -= n;
ptr2 -= n;
}
Registers.ES += 0x1000;
ptr = 0;
}
new Inline("pop es");
}
public static ushort SearchFile(string fn)
{
new Inline("push es");
Registers.ES = FDC.FATSeg;
ushort ptr = 0, ret = 0;
string fn2 = FDC.ConvertFileName(fn);
for (ushort i = 0; i < FDC.RDE; i++, ptr += 0x20)
{
if (Str.StartsWith(fn2, ptr))
{
Registers.DI = (ushort)(ptr + 0x1a); // start sector
new Inline("mov ax, [es:di]");
ret = Registers.AX;
break;
}
}
new Inline("pop es");
return(ret);
}