Skip to content

Commit

Permalink
Floppy controller/drives re-worked
Browse files Browse the repository at this point in the history
  • Loading branch information
@nzeemin
nzeemin committed Jan 8, 2025
1 parent 4f21ce4 commit d5103b9
Show file tree
Hide file tree
Showing 3 changed files with 80 additions and 55 deletions.
2 changes: 1 addition & 1 deletion emulator/emubase/Board.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -364,7 +364,7 @@ bool CMotherboard::SystemFrame()
const int audioticks = 20286 / (SOUNDSAMPLERATE / 25);
m_SoundChanges = 0;
const int teletypeTicks = 20000 / (9600 / 25);
int floppyTicks = (m_Configuration & BK_COPT_BK0011) ? 38 : 44;
int floppyTicks = (m_Configuration & BK_COPT_BK0011) ? 38 : 32;
int teletypeTxCount = 0;

int frameTapeTicks = 0, tapeSamplesPerFrame = 0, tapeReadError = 0;
Expand Down
13 changes: 7 additions & 6 deletions emulator/emubase/Emubase.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -53,14 +53,14 @@ int Disasm_GetInstructionHint(

#define FLOPPY_FSM_IDLE 0

#define FLOPPY_CMD_CORRECTION250 04
#define FLOPPY_CMD_CORRECTION500 010
#define FLOPPY_CMD_ENGINESTART 020
#define FLOPPY_CMD_SIDEUP 040
#define FLOPPY_CMD_DIR 0100
#define FLOPPY_CMD_STEP 0200
#define FLOPPY_CMD_SEARCHSYNC 0400
#define FLOPPY_CMD_SKIPSYNC 01000
#define FLOPPY_CMD_READDATA 0400
#define FLOPPY_CMD_WRITEMARKER 01000
#define FLOPPY_CMD_PRECORRECTION 02000

//dir == 0 to center (towards trk0)
//dir == 1 from center (towards trk80)

Expand Down Expand Up @@ -108,6 +108,7 @@ class CFloppyController
bool m_shiftflag; // Write mode shift register has data
bool m_shiftmarker; // Write marker in m_marker
bool m_writing; // TRUE = write mode, false = read mode
bool m_searchsynctrig; // Search for sync trigger
bool m_searchsync; // Read sub-mode: TRUE = search for sync, false = just read
bool m_crccalculus; // TRUE = CRC is calculated now
bool m_trackchanged; // TRUE = m_data was changed - need to save it into the file
Expand All @@ -124,8 +125,8 @@ class CFloppyController
bool IsAttached(int drive) const { return (m_drivedata[drive].fpFile != nullptr); }
bool IsReadOnly(int drive) const { return m_drivedata[drive].okReadOnly; } // return (m_status & FLOPPY_STATUS_WRITEPROTECT) != 0; }
bool IsEngineOn() { return (m_flags & FLOPPY_CMD_ENGINESTART) != 0; }
uint16_t GetData(void); // Reading port 177132 - data
uint16_t GetState(void); // Reading port 177130 - device status
uint16_t GetData(); // Reading port 177132 - data
uint16_t GetState(); // Reading port 177130 - device status
uint16_t GetDataView() const { return m_datareg; } // Get port 177132 value for debugger
uint16_t GetStateView() const { return m_status; } // Get port 177130 value for debugger
void SetCommand(uint16_t cmd); // Writing to port 177130 - commands
Expand Down
120 changes: 72 additions & 48 deletions emulator/emubase/Floppy.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,8 +22,9 @@ BKBTL. If not, see <http://www.gnu.org/licenses/>. */

// Маска флагов, сохраняемых в m_flags
const uint16_t FLOPPY_CMD_MASKSTORED =
FLOPPY_CMD_CORRECTION250 | FLOPPY_CMD_CORRECTION500 | FLOPPY_CMD_SIDEUP | FLOPPY_CMD_DIR | FLOPPY_CMD_SKIPSYNC |
FLOPPY_CMD_ENGINESTART;
0x000F | // Floppy drive selection bits
FLOPPY_CMD_ENGINESTART | FLOPPY_CMD_SIDEUP | FLOPPY_CMD_DIR | FLOPPY_CMD_STEP | FLOPPY_CMD_READDATA |
FLOPPY_CMD_WRITEMARKER | FLOPPY_CMD_PRECORRECTION;

static void EncodeTrackData(const uint8_t* pSrc, uint8_t* data, uint8_t* marker, uint16_t track, uint16_t side);
static bool DecodeTrackData(const uint8_t* pRaw, uint8_t* pDest);
Expand Down Expand Up @@ -53,14 +54,16 @@ void CFloppyDrive::Reset()

CFloppyController::CFloppyController()
{
m_drive = m_side = m_track = 0;
m_side = m_track = 0;
m_drive = -1;
m_pDrive = nullptr;
m_datareg = m_writereg = m_shiftreg = 0;
m_searchsynctrig = false;
m_writing = m_searchsync = m_writemarker = m_crccalculus = false;
m_writeflag = m_shiftflag = m_shiftmarker = false;
m_trackchanged = false;
m_status = FLOPPY_STATUS_TRACK0 | FLOPPY_STATUS_WRITEPROTECT;
m_flags = FLOPPY_CMD_CORRECTION500 | FLOPPY_CMD_SIDEUP | FLOPPY_CMD_DIR | FLOPPY_CMD_SKIPSYNC;
m_status = FLOPPY_STATUS_TRACK0;
m_flags = FLOPPY_CMD_SIDEUP | FLOPPY_CMD_DIR | FLOPPY_CMD_WRITEMARKER;
m_okTrace = false;
}

Expand All @@ -72,16 +75,20 @@ CFloppyController::~CFloppyController()

void CFloppyController::Reset()
{
if (m_okTrace) DebugLog(_T("Floppy RESET\r\n"));

FlushChanges();

m_drive = m_side = m_track = 0;
m_side = m_track = 0;
m_drive = -1;
m_pDrive = nullptr;
m_datareg = m_writereg = m_shiftreg = 0;
m_searchsynctrig = false;
m_writing = m_searchsync = m_writemarker = m_crccalculus = false;
m_writeflag = m_shiftflag = false;
m_trackchanged = false;
m_status = FLOPPY_STATUS_TRACK0 | FLOPPY_STATUS_WRITEPROTECT;
m_flags = FLOPPY_CMD_CORRECTION500 | FLOPPY_CMD_SIDEUP | FLOPPY_CMD_DIR | FLOPPY_CMD_SKIPSYNC;
m_status = FLOPPY_STATUS_TRACK0;
m_flags = FLOPPY_CMD_SIDEUP | FLOPPY_CMD_DIR | FLOPPY_CMD_WRITEMARKER;

PrepareTrack();
}
Expand Down Expand Up @@ -111,8 +118,8 @@ bool CFloppyController::AttachImage(int drive, LPCTSTR sFileName)
m_writing = m_searchsync = m_writemarker = m_crccalculus = false;
m_writeflag = m_shiftflag = false;
m_trackchanged = false;
m_status = FLOPPY_STATUS_TRACK0 | FLOPPY_STATUS_WRITEPROTECT;
m_flags = FLOPPY_CMD_CORRECTION500 | FLOPPY_CMD_SIDEUP | FLOPPY_CMD_DIR | FLOPPY_CMD_SKIPSYNC;
m_status = (m_pDrive != nullptr && m_pDrive->okReadOnly) ? FLOPPY_STATUS_TRACK0 | FLOPPY_STATUS_WRITEPROTECT : FLOPPY_STATUS_TRACK0;
m_flags = FLOPPY_CMD_SIDEUP | FLOPPY_CMD_DIR | FLOPPY_CMD_WRITEMARKER;

PrepareTrack();

Expand All @@ -134,7 +141,7 @@ void CFloppyController::DetachImage(int drive)
//////////////////////////////////////////////////////////////////////


uint16_t CFloppyController::GetState(void)
uint16_t CFloppyController::GetState()
{
if (m_pDrive == nullptr)
return 0;
Expand All @@ -146,55 +153,48 @@ uint16_t CFloppyController::GetState(void)
else
m_status &= ~FLOPPY_STATUS_TRACK0;

if (m_pDrive->dataptr >= FLOPPY_RAWTRACKSIZE - FLOPPY_INDEXLENGTH)
if (m_pDrive->dataptr < FLOPPY_INDEXLENGTH)
m_status |= FLOPPY_STATUS_INDEXMARK;
else
m_status &= ~FLOPPY_STATUS_INDEXMARK;

uint16_t res = m_status /*| FLOPPY_STATUS_RDY*/;

// if (res & FLOPPY_STATUS_MOREDATA)
// DebugLogFormat(_T("Floppy GET STATE %06o\r\n"), res);
if (IsEngineOn())
m_status |= FLOPPY_STATUS_RDY;
else
m_status &= ~(FLOPPY_STATUS_RDY | FLOPPY_STATUS_MOREDATA | FLOPPY_STATUS_CHECKSUMOK);

return res;
return m_status;
}

void CFloppyController::SetCommand(uint16_t cmd)
{
// if (m_okTrace)
// DebugLogFormat(_T("Floppy COMMAND %06o\r\n"), cmd);

// Copy new flags to m_flags
m_flags &= ~FLOPPY_CMD_MASKSTORED;
m_flags |= cmd & FLOPPY_CMD_MASKSTORED;

bool okPrepareTrack = false; // Нужно ли считывать дорожку в буфер

// Проверить, не сменился ли текущий привод
int newdrive = -1;
switch (cmd & 0x0f)
{
case 0: newdrive = -1; break;
case 1: default: newdrive = 0; break;
case 2: case 6: case 10: case 14: newdrive = 1; break;
case 4: case 12: newdrive = 2; break;
case 8: newdrive = 3; break;
}
// Проверить, не сменился ли текущий привод;
// тут выбирается текущий привод, чем более младший бит, тем больше приоритет;
// если установлено несколько битов - выбирается тот, что младше.
int newdrive = (cmd & 1) ? 0 : (cmd & 2) ? 1 : (cmd & 4) ? 2 : (cmd & 8) ? 3 : -1;

if (m_drive != newdrive)
{
FlushChanges();

m_drive = newdrive;
m_pDrive = (newdrive == -1) ? NULL : m_drivedata + m_drive;
m_pDrive = (newdrive == -1) ? nullptr : m_drivedata + m_drive;
okPrepareTrack = true;

if (m_okTrace)
DebugLogFormat(_T("Floppy CURRENT DRIVE %d\r\n"), newdrive);
}
if (m_drive == -1)
return;
cmd &= ~3; // Убираем из команды информацию о текущем приводе

// Copy new flags to m_flags
m_flags &= ~FLOPPY_CMD_MASKSTORED;
m_flags |= cmd & FLOPPY_CMD_MASKSTORED;

// Проверяем, не сменилась ли сторона
if (m_flags & FLOPPY_CMD_SIDEUP) // Side selection: 0 - down, 1 - up
Expand All @@ -206,13 +206,11 @@ case 1: default: newdrive = 0; break;
if (m_side == 1) { m_side = 0; okPrepareTrack = true; }
}

if (cmd & FLOPPY_CMD_STEP) // Move head for one track to center or from center
if (m_flags & FLOPPY_CMD_STEP) // Move head for one track to center or from center
{
if (m_okTrace)
DebugLogFormat(_T("Floppy STEP %d\r\n"), (m_flags & FLOPPY_CMD_DIR) ? 1 : 0);

m_side = (m_flags & FLOPPY_CMD_SIDEUP) ? 1 : 0;

if (m_flags & FLOPPY_CMD_DIR)
{
if (m_track < 82) { m_track++; okPrepareTrack = true; }
Expand All @@ -221,27 +219,34 @@ case 1: default: newdrive = 0; break;
{
if (m_track >= 1) { m_track--; okPrepareTrack = true; }
}

if (m_track == 0)
m_status |= FLOPPY_STATUS_TRACK0;
else
m_status &= ~FLOPPY_STATUS_TRACK0;
}
if (okPrepareTrack)
PrepareTrack();

if (cmd & FLOPPY_CMD_SEARCHSYNC) // Search for marker
if (m_flags & FLOPPY_CMD_READDATA) // Search for marker
{
if (m_okTrace)
DebugLog(_T("Floppy SEARCHSYNC\r\n"));

m_flags &= ~FLOPPY_CMD_SEARCHSYNC;
m_searchsynctrig = true;
}
else if (m_searchsynctrig)
{
m_searchsynctrig = false;
m_searchsync = true;
m_crccalculus = true;
m_status &= ~FLOPPY_STATUS_CHECKSUMOK;
m_status &= ~(FLOPPY_STATUS_CHECKSUMOK | FLOPPY_STATUS_MOREDATA);
}

if (m_writing && (cmd & FLOPPY_CMD_SKIPSYNC)) // Запись маркера
if (m_writing && (cmd & FLOPPY_CMD_WRITEMARKER)) // Запись маркера
{
// DebugLog(_T("Floppy MARKER\r\n")); //DEBUG

m_writemarker = true;
m_status &= ~FLOPPY_STATUS_CHECKSUMOK;
m_status &= ~(FLOPPY_STATUS_CHECKSUMOK | FLOPPY_STATUS_MOREDATA);
}
}

Expand Down Expand Up @@ -494,6 +499,22 @@ void CFloppyController::FlushChanges()
//////////////////////////////////////////////////////////////////////


uint16_t getCrc(const uint8_t *ptr, size_t len)
{
int crc = 0xffff;
while (len--)
{
uint8_t val = *ptr++;
crc ^= val << 8;
for (int i = 0; i < 8; ++i)
{
if ((crc <<= 1) & 0x10000)
crc ^= 0x1021;
}
}
return (crc & 0xffff);
}

// Fill data array and marker array with marked data
static void EncodeTrackData(const uint8_t* pSrc, uint8_t* data, uint8_t* marker, uint16_t track, uint16_t side)
{
Expand All @@ -511,32 +532,35 @@ static void EncodeTrackData(const uint8_t* pSrc, uint8_t* data, uint8_t* marker,
for (count = 0; count < 12; count++) data[ptr++] = 0x00;
// marker
marker[ptr / 2] = true; // ID marker; start CRC calculus
uint8_t *pCrcPtr = data + ptr; size_t nCrcPtr = ptr;
data[ptr++] = 0xa1; data[ptr++] = 0xa1; data[ptr++] = 0xa1;
data[ptr++] = 0xfe;

data[ptr++] = (uint8_t) track; data[ptr++] = (side != 0);
data[ptr++] = (uint8_t) track; data[ptr++] = (side == 0) ? 0 : 1;
data[ptr++] = sect + 1; data[ptr++] = 2; // Assume 512 bytes per sector;
// crc
//TODO: Calculate CRC
data[ptr++] = 0x12; data[ptr++] = 0x34; // CRC stub
uint16_t crc = getCrc(pCrcPtr, ptr - nCrcPtr);
data[ptr++] = (uint8_t)(crc & 0xff); data[ptr++] = (uint8_t)(crc >> 8);

// sync
for (count = 0; count < 22; count++) data[ptr++] = 0x4e;
// data header
for (count = 0; count < 12; count++) data[ptr++] = 0x00;
// marker
marker[ptr / 2] = true; // Data marker; start CRC calculus
pCrcPtr = data + ptr; nCrcPtr = ptr;
data[ptr++] = 0xa1; data[ptr++] = 0xa1; data[ptr++] = 0xa1;
data[ptr++] = 0xfb;
// data
for (count = 0; count < 512; count++)
data[ptr++] = pSrc[(sect * 512) + count];
// crc
//TODO: Calculate CRC
data[ptr++] = 0x43; data[ptr++] = 0x21; // CRC stub
crc = getCrc(pCrcPtr, ptr - nCrcPtr);
data[ptr++] = (uint8_t)(crc & 0xff); data[ptr++] = (uint8_t)(crc >> 8);

gap = 36; // GAP3 length
}

// fill GAP4B to the end of the track
while (ptr < FLOPPY_RAWTRACKSIZE) data[ptr++] = 0x4e;
}
Expand Down

0 comments on commit d5103b9

Please sign in to comment.