github.com/livingcomputermuseum.ContrAlto
1
0
Fork 0
mirror of https://github.com/livingcomputermuseum/ContrAlto.git synced 2026-02-14 03:44:58 +00:00
Code Issues Releases Wiki Activity

Fixed Trident drive select issues, corrected issue with extended memory bank registers. IFS now runs.

Browse Source
This commit is contained in:
Josh Dersch
2017-08-31 12:23:46 -07:00
parent 523a4bb27f
commit 38124350fb
12 changed files with 227 additions and 138 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
Contralto/Memory/Memory.cs
View File

@@ -56,24 +56,42 @@ namespace Contralto.Memory
get { return _memTop; }
}
/// <summary>
/// Full reset, clears all memory.
/// </summary>
public void Reset()
{
// 4 64K banks, regardless of system type. (Alto Is just won't use the extra memory.)
_mem = new ushort[0x40000];
_xmBanks = new ushort[16];
_xmBanksAlternate = new int[16];
_xmBanksNormal = new int[16];
}
/// <summary>
/// Soft reset, clears XM bank registers.
/// </summary>
public void SoftReset()
{
_xmBanks = new ushort[16];
_xmBanksAlternate = new int[16];
_xmBanksNormal = new int[16];
}
public ushort Read(int address, TaskType task, bool extendedMemory)
{
// Check for XM registers; this occurs regardless of XM flag since it's in the I/O page.
if (address >= _xmBanksStart && address < _xmBanksStart + 16)
{
{
// NB: While not specified in documentatino, some code (IFS in particular) relies on the fact that
// the upper 12 bits of the bank registers are all 1s.
return (ushort)(0xfff0 | _xmBanks[address - _xmBanksStart]);
}
else
{
address += 0x10000 * GetBankNumber(task, extendedMemory);
return _mem[address];
return _mem[address];
}
}
@@ -81,17 +99,22 @@ namespace Contralto.Memory
{
// Check for XM registers; this occurs regardless of XM flag since it's in the I/O page.
if (address >= _xmBanksStart && address < _xmBanksStart + 16)
{
{
_xmBanks[address - _xmBanksStart] = data;
// Precalc bank numbers to speed memory accesses that use them
_xmBanksAlternate[address - _xmBanksStart] = data & 0x3;
_xmBanksNormal[address - _xmBanksStart] = (data & 0xc) >> 2;
Log.Write(LogComponent.Memory, "XM register for task {0} set to bank {1} (normal), {2} (xm)",
(TaskType)(address - _xmBanksStart),
(data & 0xc) >> 2,
(data & 0x3));
(data & 0x3));
}
else
{
address += 0x10000 * GetBankNumber(task, extendedMemory);
_mem[address] = data;
_mem[address] = data;
}
}
@@ -102,7 +125,7 @@ namespace Contralto.Memory
private int GetBankNumber(TaskType task, bool extendedMemory)
{
return extendedMemory ? (_xmBanks[(int)task]) & 0x3 : ((_xmBanks[(int)task]) & 0xc) >> 2;
return extendedMemory ? _xmBanksAlternate[(int)task] : _xmBanksNormal[(int)task];
}
private readonly MemoryRange[] _addresses;
@@ -112,6 +135,8 @@ namespace Contralto.Memory
private ushort[] _mem;
private ushort[] _xmBanks;
private ushort[] _xmBanks;
private int[] _xmBanksAlternate;
private int[] _xmBanksNormal;
}
}