AppleWin/source/DiskFormatTrack.cpp

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/*
AppleWin : An Apple //e emulator for Windows
Copyright (C) 1994-1996, Michael O'Brien
Copyright (C) 1999-2001, Oliver Schmidt
Copyright (C) 2002-2005, Tom Charlesworth
Copyright (C) 2006-2017, Tom Charlesworth, Michael Pohoreski, Nick Westgate
AppleWin is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
AppleWin is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with AppleWin; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* Description: Disk][ format track support
*
* Author: Various
*/
#include "StdAfx.h"
#include "Disk.h"
#include "DiskLog.h"
#include "DiskFormatTrack.h"
#include "Log.h"
#include "YamlHelper.h"
// Occurs on these conditions:
// . ctor
// . disk][ reset
void FormatTrack::Reset(void)
{
memset(m_VolTrkSecChk, 0, sizeof(m_VolTrkSecChk));
memset(m_VolTrkSecChk4and4, 0, sizeof(m_VolTrkSecChk4and4));
m_trackState = TS_GAP1;
m_uLast3Bytes = 0;
m_4and4idx = 0;
DriveNotWritingTrack();
}
// Occurs on these conditions:
// . spin > 2 bytes (empirical from inspecting DOS3.3-INIT/ProDOS-FORMAT operations)
// . drive stepper track change
// . drive motor state change
// . switch to read mode after having written a complete track
void FormatTrack::DriveNotWritingTrack(void)
{
m_bmWrittenSectorAddrFields = 0x0000;
m_WriteTrackStartIndex = 0;
m_WriteTrackHasWrapped = false;
m_WriteDataFieldPrologueCount = 0;
#if LOG_DISK_NIBBLES_WRITE_TRACK_GAPS
m_DbgGap1Size = 0;
m_DbgGap2Size = 0;
m_DbgGap3Size = -1; // Data Field's epilogue has an extra 0xFF, which isn't part of the Gap3 sync-FF field
#endif
}
void FormatTrack::UpdateOnWriteLatch(UINT uSpinNibbleCount, const Disk_t* const fptr)
{
if (fptr->bWriteProtected)
return;
if (m_bmWrittenSectorAddrFields == 0x0000)
{
if (m_WriteTrackStartIndex == (UINT)-1) // waiting for 1st write?
m_WriteTrackStartIndex = fptr->byte;
return;
}
// Written at least 1 sector
if (m_WriteTrackHasWrapped)
return;
if (uSpinNibbleCount > 2)
{
_ASSERT(0); // Not seen this case yet
DriveNotWritingTrack();
return;
}
UINT uTrackIndex = fptr->byte;
const UINT& kTrackMaxNibbles = fptr->nibbles;
// NB. spin in write mode is only max 1-2 bytes
do
{
if (m_WriteTrackStartIndex == uTrackIndex) // disk has completed a revolution
{
// Occurs for: .dsk & enhance=0|1 & ProDOS-FORMAT/DOS3.3-INIT with big gap3 size (as trackimage is only 0x18F0 in size)
m_WriteTrackHasWrapped = true;
// Now wait until drive switched from write to read mode
return;
}
uTrackIndex = (uTrackIndex+1) % kTrackMaxNibbles;
}
while (uSpinNibbleCount--);
}
void FormatTrack::DriveSwitchedToReadMode(Disk_t* const fptr)
{
if (m_bmWrittenSectorAddrFields != 0xFFFF || m_WriteDataFieldPrologueCount != 16) // written all 16 sectors?
return;
// Zero-fill the remainder of the track buffer:
// Either up to 0x18F0 (if less than 0x18F0) or up to 0x1A00 (for .nib).
// When there's no spin (enhanced=1), then 0x18F0 is still too long, eg: (see GH#125)
// Gap1 = 0x81, Gap2 = 0x05, Gap3 = 0x1D (29), TrackSize = 0x1963
// Gap1 = 0x81, Gap2 = 0x05, Gap3 = 0x1C (28), TrackSize = 0x1954
// Gap1 = 0x81, Gap2 = 0x05, Gap3 = 0x1B (27), TrackSize = 0x1945
// Gap1 = 0x81, Gap2 = 0x05, Gap3 = 0x1A (26), TrackSize = 0x1936
//
// And 0x1936 - 0x81(gap1) = 0x18B5
// So need a track size between 0x18B0 (rounding down) and 0x182F
const UINT kShortTrackLen = 0x18B0;
LPBYTE TrackBuffer = fptr->trackimage;
const UINT kLongTrackLen = fptr->nibbles;
UINT uWriteTrackEndIndex = fptr->byte;
UINT uWrittenTrackSize = m_WriteTrackHasWrapped ? kLongTrackLen : 0;
if (m_WriteTrackStartIndex <= uWriteTrackEndIndex)
uWrittenTrackSize += uWriteTrackEndIndex - m_WriteTrackStartIndex;
else
uWrittenTrackSize += (kLongTrackLen - m_WriteTrackStartIndex) + uWriteTrackEndIndex;
#if LOG_DISK_NIBBLES_WRITE_TRACK_GAPS
LOG_DISK("Gap1 = 0x%02X, Gap2 = 0x%02X, Gap3 = 0x%02X (%02d), TrackSize = 0x%04X\n", m_DbgGap1Size, m_DbgGap2Size, m_DbgGap3Size, m_DbgGap3Size, uWrittenTrackSize);
#endif
if (uWrittenTrackSize > kShortTrackLen)
uWrittenTrackSize = kShortTrackLen;
int iSrc = uWriteTrackEndIndex - uWrittenTrackSize; // Rewind to start of non-overwritten part of short track
if (iSrc < 0)
iSrc += kLongTrackLen;
// S < E: | S-------E |
// S > E: |----E S---|
if ((UINT)iSrc < uWriteTrackEndIndex)
{
memset(&TrackBuffer[0], 0, iSrc);
memset(&TrackBuffer[uWriteTrackEndIndex], 0, kLongTrackLen - uWriteTrackEndIndex);
}
else
{
// NB. For the iSrc == uWriteTrackEndIndex case: memset() size=0
memset(&TrackBuffer[uWriteTrackEndIndex], 0, iSrc - uWriteTrackEndIndex);
}
// NB. No need to skip the zero nibbles, as INIT/FORMAT's 'read latch until high bit' loop will just consume these
DriveNotWritingTrack();
}
void FormatTrack::DriveSwitchedToWriteMode(UINT uTrackIndex)
{
// ProDOS/DOS3.3: during track write, switches to read mode then back to write mode:
// . between Address Field & Gap2; and between Data Field & Gap3
// . so if at TS_GAP2_START then stay at TS_GAP2_START
if (m_trackState != TS_GAP2_START)
m_trackState = (m_bmWrittenSectorAddrFields == 0x0000) ? TS_GAP1 : TS_GAP3;
m_uLast3Bytes = 0;
m_4and4idx = 0;
if (m_bmWrittenSectorAddrFields == 0x0000) // written no sectors
{
m_WriteTrackStartIndex = (UINT)-1; // wait for 1st write
}
}
// This is just for debug/logging: used to output when a new Address Field has been read
void FormatTrack::DecodeLatchNibbleRead(BYTE floppylatch)
{
DecodeLatchNibble(floppylatch, false);
}
void FormatTrack::DecodeLatchNibbleWrite(BYTE floppylatch, UINT uSpinNibbleCount, const Disk_t* const fptr)
{
DecodeLatchNibble(floppylatch, true);
UpdateOnWriteLatch(uSpinNibbleCount, fptr);
}
void FormatTrack::DecodeLatchNibble(BYTE floppylatch, BOOL bIsWrite)
{
m_uLast3Bytes <<= 8;
m_uLast3Bytes |= floppylatch;
m_uLast3Bytes &= 0xFFFFFF;
if (m_trackState == TS_GAP2_START && bIsWrite) // NB. bIsWrite, as there's a read between writing Addr Field & Gap2
m_trackState = TS_GAP2;
#if LOG_DISK_NIBBLES_WRITE_TRACK_GAPS
if (floppylatch == 0xFF && bIsWrite && (m_trackState == TS_GAP1 || m_trackState == TS_GAP2 || m_trackState == TS_GAP3))
{
if (m_bmWrittenSectorAddrFields == 0x0000 && m_trackState == TS_GAP1)
m_DbgGap1Size++;
else if (m_bmWrittenSectorAddrFields == 0x0001 && m_trackState == TS_GAP2)
m_DbgGap2Size++; // Only count Gap2 after sector0 Addr Field (assume other inter-sectors gap2's have same count)
else if (m_bmWrittenSectorAddrFields == 0x0001 && m_trackState == TS_GAP3)
m_DbgGap3Size++; // Only count Gap3 between sector0 & 1 (assume other inter-sectors gap3's have same count)
return;
}
#endif
// Beneath Apple ProDOS 3-14: NB. $D5 and $AA are reserved (never written as data)
if (m_uLast3Bytes == 0xD5AA96)
{
m_trackState = TS_ADDRFIELD;
m_4and4idx = 0;
return;
}
// NB. If TS_ADDRFIELD && m_4and4idx == 8, then writing Address Field's epilogue
if (m_trackState == TS_ADDRFIELD && m_4and4idx < 8)
{
m_VolTrkSecChk4and4[m_4and4idx++] = floppylatch;
if (m_4and4idx == 8)
{
for (UINT i=0; i<4; i++)
m_VolTrkSecChk[i] = ((m_VolTrkSecChk4and4[i*2] & 0x55) << 1) | (m_VolTrkSecChk4and4[i*2+1] & 0x55);
#if LOG_DISK_NIBBLES_READ
if (!bIsWrite)
{
LOG_DISK("read D5AA96 detected - Vol:%02X Trk:%02X Sec:%02X Chk:%02X\r\n", m_VolTrkSecChk[0], m_VolTrkSecChk[1], m_VolTrkSecChk[2], m_VolTrkSecChk[3]);
}
#endif
#if LOG_DISK_NIBBLES_WRITE
if (bIsWrite)
{
LOG_DISK("write D5AA96 detected - Vol:%02X Trk:%02X Sec:%02X Chk:%02X\r\n", m_VolTrkSecChk[0], m_VolTrkSecChk[1], m_VolTrkSecChk[2], m_VolTrkSecChk[3]);
}
#endif
if (bIsWrite)
{
// NB. Address Field only written when formatting track
BYTE sector = m_VolTrkSecChk[2];
_ASSERT( sector <= 15 );
if (sector > 15) // Ignore exotic formats with >16 sectors!
return;
_ASSERT( (m_bmWrittenSectorAddrFields & (1<<sector)) == 0 );
m_bmWrittenSectorAddrFields |= (1<<sector);
}
}
return;
}
#if LOG_DISK_NIBBLES_WRITE_TRACK_GAPS
if (m_uLast3Bytes == 0xDEAAEB && bIsWrite) // NB. bIsWrite, as reads could start reading anywhere
{
if (m_trackState == TS_ADDRFIELD)
{
m_trackState = TS_GAP2_START;
}
else // m_trackState == TS_DATAFIELD
{
_ASSERT(m_trackState == TS_DATAFIELD);
m_trackState = TS_GAP3;
}
return;
}
#endif
if (m_uLast3Bytes == 0xD5AAAD)
{
m_trackState = TS_DATAFIELD;
if (bIsWrite) // NB. Data Field written every time a sector is written
m_WriteDataFieldPrologueCount++;
_ASSERT(m_WriteDataFieldPrologueCount <= 16);
}
}
//===========================================================================
#define SS_YAML_KEY_FORMAT_TRACK "Format Track state"
// NB. No version - this is determined by the parent "Disk][" unit
#define SS_YAML_KEY_WRITTEN_SECTOR_ADDR_FIELDS "Written Sector Address Fields"
#define SS_YAML_KEY_WRITE_TRACK_START_IDX "Write Track Start Index"
#define SS_YAML_KEY_WRITE_TRACK_HAS_WRAPPED "Write Track Wrapped"
#define SS_YAML_KEY_WRITE_DATA_FIELD_PROLOGUE_COUNT "Write Data Field Prologue Count"
#define SS_YAML_KEY_TRACK_STATE "Track State"
#define SS_YAML_KEY_LAST3BYTES "Last 3 bytes"
#define SS_YAML_KEY_VTSC_4AND4 "Vol,Trk,Sec,Chk (4 and 4)"
#define SS_YAML_KEY_VTSC_4AND4_IDX "Index (4 and 4)"
void FormatTrack::SaveSnapshot(class YamlSaveHelper& yamlSaveHelper)
{
YamlSaveHelper::Label label(yamlSaveHelper, "%s:\n", SS_YAML_KEY_FORMAT_TRACK);
yamlSaveHelper.SaveHexUint16(SS_YAML_KEY_WRITTEN_SECTOR_ADDR_FIELDS, m_bmWrittenSectorAddrFields);
yamlSaveHelper.SaveHexUint16(SS_YAML_KEY_WRITE_TRACK_START_IDX, m_WriteTrackStartIndex);
yamlSaveHelper.SaveBool(SS_YAML_KEY_WRITE_TRACK_HAS_WRAPPED, m_WriteTrackHasWrapped);
yamlSaveHelper.SaveHexUint8(SS_YAML_KEY_WRITE_DATA_FIELD_PROLOGUE_COUNT, m_WriteDataFieldPrologueCount);
yamlSaveHelper.SaveHexUint8(SS_YAML_KEY_TRACK_STATE, m_trackState);
yamlSaveHelper.SaveHexUint24(SS_YAML_KEY_LAST3BYTES, m_uLast3Bytes);
yamlSaveHelper.SaveHexUint64(SS_YAML_KEY_VTSC_4AND4, *(UINT64*)m_VolTrkSecChk4and4); // Stored in reverse order
yamlSaveHelper.SaveHexUint4(SS_YAML_KEY_VTSC_4AND4_IDX, m_4and4idx);
}
void FormatTrack::LoadSnapshot(class YamlLoadHelper& yamlLoadHelper)
{
if (!yamlLoadHelper.GetSubMap(SS_YAML_KEY_FORMAT_TRACK))
throw std::string("Card: Expected key: ") + std::string(SS_YAML_KEY_FORMAT_TRACK);
m_bmWrittenSectorAddrFields = yamlLoadHelper.LoadUint(SS_YAML_KEY_WRITTEN_SECTOR_ADDR_FIELDS);
m_WriteTrackStartIndex = yamlLoadHelper.LoadUint(SS_YAML_KEY_WRITE_TRACK_START_IDX);
m_WriteTrackHasWrapped = yamlLoadHelper.LoadBool(SS_YAML_KEY_WRITE_TRACK_HAS_WRAPPED);
m_WriteDataFieldPrologueCount = yamlLoadHelper.LoadUint(SS_YAML_KEY_WRITE_DATA_FIELD_PROLOGUE_COUNT);
m_trackState = (TRACKSTATE_e) yamlLoadHelper.LoadUint(SS_YAML_KEY_TRACK_STATE);
m_uLast3Bytes = yamlLoadHelper.LoadUint(SS_YAML_KEY_LAST3BYTES);
*(UINT64*)m_VolTrkSecChk4and4 = yamlLoadHelper.LoadUint64(SS_YAML_KEY_VTSC_4AND4);
m_4and4idx = yamlLoadHelper.LoadUint(SS_YAML_KEY_VTSC_4AND4_IDX);
yamlLoadHelper.PopMap();
}