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updated keyscanning code

This commit is contained in:
Asnivor 2017-12-01 14:34:45 +00:00
parent a9f8828063
commit 42db947939
2 changed files with 40 additions and 23 deletions
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58
BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/SpectrumBase.Port.cs
View File

@ -24,29 +24,22 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
/// <returns></returns>
public virtual byte ReadPort(ushort port)
{
CPU.TotalExecutedCycles += 4;
int result = 0xFF;
// get the high byte from Regs[6]
ushort high = CPU.Regs[6];
// combine the low byte (passed in as port) and the high byte (maybe not needed)
//ushort word = Convert.ToUInt16((port << 8 | high));
int word = (high << 8) + port;
//port += (ushort)(CPU.Regs[CPU.A] << 8);
// Check whether the low bit is reset
// Technically the ULA should respond to every even I/O address
bool lowBitReset = (word & 0x0001) == 0;
bool lowBitReset = (port & 0x0001) == 0;
ContendPort((ushort)port);
// Kempston Joystick
//not implemented yet
if (port == 0x1f)
{
if (port == 254)
{
}
else if (lowBitReset)
{
// Even I/O address so get input
// The high byte indicates which half-row of keys is being polled
/*
@ -57,6 +50,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
0xf7fe 1, 2, 3, 4, 5 0x7ffe SPACE, SYM SHFT, M, N, B
*/
result &= KeyboardDevice.GetLineStatus((byte)(port >> 8));
/*
if (high == 0xfe)
result &= KeyboardDevice.KeyLine[0];
if (high == 0xfd)
@ -73,7 +68,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
result &= KeyboardDevice.KeyLine[6];
if (high == 0x7f)
result &= KeyboardDevice.KeyLine[7];
*/
result = result & 0x1f; //mask out lower 4 bits
result = result | 0xa0; //set bit 5 & 7 to 1
@ -150,11 +145,11 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
/// <param name="value"></param>
public virtual void WritePort(ushort port, byte value)
{
CPU.TotalExecutedCycles += 4;
// Check whether the low bit is reset
// Technically the ULA should respond to every even I/O address
bool lowBitReset = (port & 0x0001) == 0;
bool lowBitReset = (port & 0x01) == 0;
ContendPort(port);
// Only even addresses address the ULA
if (lowBitReset)
@ -179,5 +174,28 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
TapeDevice.ProcessMicBit((value & MIC_BIT) != 0);
}
}
/// <summary>
/// Apply I/O contention if necessary
/// </summary>
/// <param name="port"></param>
public virtual void ContendPort(ushort port)
{
var lowBit = (port & 0x0001) != 0;
var ulaHigh = (port & 0xc000) == 0x4000;
var cfc = CurrentFrameCycle;
if (cfc < 1)
cfc = 1;
if (ulaHigh)
{
CPU.TotalExecutedCycles += GetContentionValue(cfc - 1);
}
else
{
if (!lowBit)
CPU.TotalExecutedCycles += GetContentionValue(cfc);
}
}
}
}

5
BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum48K/ZX48.Keyboard.cs
View File

@ -273,8 +273,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
}
public byte GetLineStatus(byte lines)
{
{
lock(this)
{
byte status = 0;
@ -287,7 +286,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
lineIndex++;
lines >>= 1;
}
var result = (byte)~status;
var result = (byte)status;
return result;
}