Method ReadTrack

source/Disk.cpp:304–400

//===========================================================================

void Disk2InterfaceCard::ReadTrack(const int drive, ULONG uExecutedCycles)
{
	if (!IsDriveValid( drive ))
		return;

	FloppyDrive* pDrive = &m_floppyDrive[ drive ];
	FloppyDisk* pFloppy = &pDrive->m_disk;

	if (ImagePhaseToTrack(pFloppy->m_imagehandle, pDrive->m_phasePrecise, false) >= ImageGetNumTracks(pFloppy->m_imagehandle))
	{
		if (ImageIsZeroTracksValidForThisType(pFloppy->m_imagehandle))
			return;

		_ASSERT(0);	// What can cause this? Add a comment to replace this assert.
		// Boot with DOS 3.3 Master in D1
		// Create a blank disk in D2
		// INIT HELLO,D2
		// RUN HELLO
		// F2 to reboot DOS 3.3 Master
		// RUN HELLO,D2
		pFloppy->m_trackimagedata = false;
		return;
	}

	if (!pFloppy->m_trackimage)
		AllocTrack( drive );

	if (pFloppy->m_trackimage && pFloppy->m_imagehandle)
	{
		if (ImageIsWOZ(pFloppy->m_imagehandle))
		{
			// Update bitStream position for *current* track before re-calc'ing position for new track
			UINT bitCellDelta = GetBitCellDelta(uExecutedCycles);
			UpdateBitStreamPosition(*pFloppy, bitCellDelta);
		}

		if (ImageIsWOZ(pFloppy->m_imagehandle) && (pFloppy->m_bitCount == 0))
		{
			// WOZ: m_bitCount only ever 0 on initial power on
			pFloppy->m_bitOffset = 0;
			pFloppy->m_bitCount = 8;
		}

		const UINT32 currentBitPosition = pFloppy->m_bitOffset;
		const UINT32 currentBitTrackLength = pFloppy->m_bitCount;

		ImageReadTrack(
			pFloppy->m_imagehandle,
			pDrive->m_phasePrecise,
			pFloppy->m_trackimage,
			&pFloppy->m_nibbles,
			&pFloppy->m_bitCount,
			m_enhanceDisk);

		if (!ImageIsWOZ(pFloppy->m_imagehandle))
		{
			pFloppy->m_byte = 0;
		}