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Fixed CD-ROM timings on the NCR 53x8xx SCSI controllers, the IDE_TIME, CDROM_TIME, and ZIP_TIME values, and the delay added to the CD-ROM READ SUBCHANNEL command, fixes slowdowns on several games that use CD Audio, such as Tomb Raider II.

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OBattler
2019-11-19 04:35:54 +01:00
parent 841a1f67da
commit e4408bc84d
7 changed files with 97 additions and 58 deletions
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61
src/disk/hdc_ide.c
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@@ -9,7 +9,7 @@
* Implementation of the IDE emulation for hard disks and ATAPI
* CD-ROM devices.
*
* Version: @(#)hdc_ide.c 1.0.64 2019/11/06
* Version: @(#)hdc_ide.c 1.0.65 2019/11/19
*
* Authors: Sarah Walker, <http://pcem-emulator.co.uk/>
* Miran Grca, <mgrca8@gmail.com>
@@ -109,7 +109,7 @@
#define FEATURE_DISABLE_IRQ_OVERLAPPED 0xdd
#define FEATURE_DISABLE_IRQ_SERVICE 0xde
#define IDE_TIME 20.0 / 3.0
#define IDE_TIME 10.0
typedef struct {
@@ -175,70 +175,72 @@ ide_get_drive(int ch)
double
ide_get_period(ide_t *ide, int size)
{
double period = 10.0 / 3.0;
double period = (10.0 / 3.0);
/* We assume that 1 MB = 1000000 B in this case, so we have as
many B/us as there are MB/s because 1 s = 1000000 us. */
switch(ide->mdma_mode & 0x300) {
case 0x000: /* PIO */
switch(ide->mdma_mode & 0xff) {
case 0:
period = 10.0 / 3.0;
period = (10.0 / 3.0);
break;
case 1:
period = (period * 600.0) / 383.0;
period = (20.0 / 3.83);
break;
case 2:
period = 25.0 / 3.0;
period = (25.0 / 3.0);
break;
case 3:
period = 100.0 / 9.0;
period = (100.0 / 9.0);
break;
case 4:
period = 50.0 / 3.0;
period = (50.0 / 3.0);
break;
}
break;
case 0x100: /* Single Word DMA */
switch(ide->mdma_mode & 0xff) {
case 0:
period = 25.0 / 12.0;
period = (25.0 / 12.0);
break;
case 1:
period = 25.0 / 6.0;
period = (25.0 / 6.0);
break;
case 2:
period = 25.0 / 3.0;
period = (25.0 / 3.0);
break;
}
break;
case 0x200: /* Multiword DMA */
switch(ide->mdma_mode & 0xff) {
case 0:
period = 25.0 / 6.0;
period = (25.0 / 6.0);
break;
case 1:
period = 40.0 / 3.0;
period = (40.0 / 3.0);
break;
case 2:
period = 50.0 / 3.0;
period = (50.0 / 3.0);
break;
}
break;
case 0x300: /* Ultra DMA */
switch(ide->mdma_mode & 0xff) {
case 0:
period = 50.0 / 3.0;
period = (50.0 / 3.0);
break;
case 1:
period = 25.0;
break;
case 2:
period = 100.0 / 3.0;
period = (100.0 / 3.0);
break;
case 3:
period = 400.0 / 9.0;
period = (400.0 / 9.0);
break;
case 4:
period = 200.0 / 3.0;
period = (200.0 / 3.0);
break;
case 5:
period = 100.0;
@@ -247,9 +249,26 @@ ide_get_period(ide_t *ide, int size)
break;
}
period *= 1048576.0; /* period * MB - get bytes per second */
period = ((double) size) / period; /* size / period to get seconds */
return period * 1000000.0; /* return seconds * 1000000 to convert to us */
period = (10.0 / 3.0);
period = (1.0 / period); /* get us for 1 byte */
return period * ((double) size); /* multiply by bytes to get period for the entire transfer */
}
double
ide_atapi_get_period(uint8_t channel)
{
ide_t *ide = ide_drives[channel];
ide_log("ide_atapi_get_period(%i)\n", channel);
if (!ide) {
ide_log("Get period failed\n");
return -1.0;
}
return ide_get_period(ide, 1);
}