Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-04-23 08:49:55 +03:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

Calculate seek time using tracks rather than sectors, assuming that reading any sector on the current track will already be in the drives cache. Zeros m_cur_lba when the drive is reset for consistency (running kinst in a debug build took 30 seconds to start) (nw)

Browse Source
This commit is contained in:
smf- 2013-11-21 01:12:08 +00:00
parent 177a1e2b30
commit 12c9bedf19
2 changed files with 26 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
src/emu/machine/idehd.c
View File

@ -14,10 +14,10 @@
#define TIME_PER_SECTOR (attotime::from_usec(100))
#define TIME_PER_ROTATION (attotime::from_hz(5400/60))
#define TIME_MULTIPLE_SECTORS (attotime::from_nsec(400))
#define TIME_BETWEEN_SECTORS (attotime::from_nsec(400))
#define TIME_SEEK_MULTISECTOR (attotime::from_usec(13000))
#define TIME_NO_SEEK_MULTISECTOR (attotime::from_usec(1300))
#define TIME_FULL_STROKE_SEEK (attotime::from_usec(13000))
#define TIME_AVERAGE_ROTATIONAL_LATENCY (attotime::from_usec(1300))
ata_mass_storage_device::ata_mass_storage_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock,const char *shortname, const char *source)
: ata_hle_device(mconfig, type, name, tag, owner, clock, shortname, source),
@ -187,6 +187,7 @@ void ata_mass_storage_device::soft_reset()
{
ata_hle_device::soft_reset();
m_cur_lba = 0;
m_status |= IDE_STATUS_DSC;
m_master_password_enable = (m_master_password != NULL);
@ -338,6 +339,25 @@ void ata_mass_storage_device::security_error()
*
*************************************/
attotime ata_mass_storage_device::seek_time()
{
/* just set a timer */
int new_lba = lba_address();
int old_cylinder = m_cur_lba / (m_num_heads * m_num_sectors);
int new_cylinder = new_lba / (m_num_heads * m_num_sectors);
int diff = abs(old_cylinder - new_cylinder);
m_cur_lba = new_lba;
if (diff == 0)
return TIME_BETWEEN_SECTORS;
attotime seek_time = (TIME_FULL_STROKE_SEEK * diff) / m_num_cylinders;
return seek_time + TIME_AVERAGE_ROTATIONAL_LATENCY;
}
void ata_mass_storage_device::fill_buffer()
{
switch (m_command)
@ -354,7 +374,7 @@ void ata_mass_storage_device::fill_buffer()
{
set_dasp(ASSERT_LINE);
start_busy(TIME_MULTIPLE_SECTORS, PARAM_COMMAND);
start_busy(TIME_BETWEEN_SECTORS, PARAM_COMMAND);
}
break;
}
@ -423,15 +443,7 @@ void ata_mass_storage_device::read_first_sector()
{
set_dasp(ASSERT_LINE);
/* just set a timer */
int new_lba = lba_address();
int diff = abs(m_cur_lba - new_lba);
int total_sectors = m_num_cylinders * m_num_heads * m_num_sectors;
attotime seek_time = TIME_NO_SEEK_MULTISECTOR + ((TIME_SEEK_MULTISECTOR * diff) / total_sectors);
start_busy(seek_time, PARAM_COMMAND);
m_cur_lba = new_lba;
start_busy(seek_time(), PARAM_COMMAND);
}
}

1
src/emu/machine/idehd.h
View File

@ -72,6 +72,7 @@ private:
void security_error();
void read_first_sector();
void soft_reset();
attotime seek_time();
UINT32 m_cur_lba;
UINT16 m_block_count;