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Merge pull request #341 from Kuba-J/main

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CD: Add optional backward seek hack (Dave Mirra, Thrasher), fix INT1 handling (Parodius, Crime Crackers, Yakyū ’95), fix DMA read from empty sector buffer (MiruMiru demo), Fix PAUSE timing
This commit is contained in:
RobertPeip
2026-01-26 19:01:53 +01:00
committed by GitHub
parent 75144be73c 0077e49225
commit 52ebfefd1a
5 changed files with 52 additions and 24 deletions
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8
PSX.sv
View File

@@ -345,7 +345,7 @@ wire reset_or = RESET | buttons[1] | status[0] | bios_download | exe_download |
// 0 1 2 3 4 5 6 7 8 9
// 01234567890123456789012345678901 23456789012345678901234567890123 45678901234567890123456789012345
// 0123456789ABCDEFGHIJKLMNOPQRSTUV 0123456789ABCDEFGHIJKLMNOPQRSTUV
// XXXX XXXXXX XXXXXX XXXXX XX XX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXX
// XXXX XXXXXX XXXXXX XXXXX XX XX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
`include "build_id.v"
parameter CONF_STR = {
@@ -423,9 +423,10 @@ parameter CONF_STR = {
"P2O[21],CD Fast Seek,Off,On(U);",
"P2O[77:75],CD Speed,Original,Forced 1X(U),Forced 2X(U),Hack 4X(U),Hack 6X(U),Hack 8X(U);",
"P2O[78],Limit Max CD Speed,Off,On(U);",
"P2O[93],Backward Seek Hack,Off,On(U);",
"P2O[85],RAM(Homebrew),2 MByte,8 MByte(U);",
"P2O[90],GPU Slowdown,Off,On(U);",
"P2O[92],Old GPU,Off,On;",
"P2O[92],Old GPU(CXD8514Q),Off,On;",
"P2-;",
"P2O[28],FPS Overlay,Off,On;",
"P2O[74],Error Overlay,Off,On;",
@@ -941,7 +942,7 @@ always @(posedge clk_1x) begin
if (!padMode[1]) psx_info <= 8'd18;
end else if (cdinfo_download_1 && ~cdinfo_download) begin
// warning for every unsafe option
if (status[89] || status[80:79] > 0 || status[72] || status[15] || status[21] || status[77:75] > 0 || status[78] || status[85]) begin
if (status[89] || status[80:79] > 0 || status[72] || status[15] || status[21] || status[77:75] > 0 || status[78] || status[85] || status[93]) begin
psx_info_req <= 1;
psx_info <= 8'd24;
end else if (status[40:39] == 2'b00) begin
@@ -1109,6 +1110,7 @@ psx
.REPRODUCIBLESPUDMA(status[43]),
.WIDESCREEN(status[54:53]),
.oldGPU(status[92]),
.backwardSeekHack(status[93]),
// RAM/BIOS interface
.biosregion(biosregion),

8
README.md
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@@ -19,6 +19,7 @@ SDRAM of any size is required.
* 8 Mbyte mode(from dev units, mostly for homebrew)
* Inputs: DualShock, Digital, Analog, Mouse, NeGcon, Wheel, Justifier and Guncon support.
* Native Input support through SNAC
* Old GPU (CXD8514Q)
## Bios
Rename your playstation bios file (e.g. `scph-1001.bin`/`ps-22a.bin` ) and place it in the `./games/PSX/` folder.
@@ -47,7 +48,7 @@ You need to save them either manually in the OSD or turn on autosave. Saving or
## Multiple Disc Games
To swap discs while the game is running, you will need have all of the disc files for the game placed in the same folder. Then when loading a new disc for most games you will need to toggle the Lid Open/Close option to tell the game you have opened the lid and closed it. Example folder structure of a multi disc game:
To swap discs while the game is running, all disc files for the game must be placed in the same folder. When a disc change is required, the core will automatically simulate opening and closing the disc lid. Example folder structure of a multi-disc game:
```
/media/fat/games/PSX/Final Fantasy VII (USA)/Final Fantasy VII (USA) (Disc 1).chd
@@ -107,6 +108,11 @@ The higher speed rates are more unstable and require proper storage to be usable
Will hold back any new CD data until the game has processed the last data.
Mostly useful to prevent CD data overrun when using higher speed modes, leading to overall faster loading times due to less read retries.
- Backward Seek Hack:
Fixes long stutters in Dave Mirra and Thrasher games related to backward CD seeks.
The drive continues reading normally, while sectors ahead of the seek target are temporarily hidden from the CPU until the correct position is reached.
Generally safe, but may affect a small number of sensitive titles (e.g. some Army Men games).
- RAM:
8 Mbyte option from development consoles. Only use for homebrew that requires it, otherwise there is a high chance of crashing games.

55
rtl/cd_top.vhd
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@@ -22,6 +22,8 @@ entity cd_top is
pauseOnCDSlow : in std_logic;
region : in std_logic_vector(1 downto 0);
region_out : out std_logic_vector(1 downto 0);
backwardSeekHack : in std_logic;
pauseCD : out std_logic := '0';
Pause_idle_cd : out std_logic := '0';
@@ -714,19 +716,24 @@ begin
end if;
end if;
if (ackRead = '1' or ackRead_data = '1') then
if (CDROM_IRQFLAG = "00001") then -- irq for sector still pending, sector missed
-- will be handled when next sector is fetched from cpu interface
elsif (CDROM_IRQFLAG /= "00000") then -- store sector done if current irq is something else, so CPU will be notified later
pendingDriveIRQ <= "00001";
pendingDriveResponse <= internalStatus;
if (ackRead = '1' or ackRead_data = '1') then
if (CDROM_IRQFLAG = "00011") then
-- INT3 active: do not overwrite it with INT1
-- queue INT1 for later delivery
if (pendingDriveIRQ = "00000") then
pendingDriveIRQ <= "00001";
pendingDriveResponse <= internalStatus;
end if;
else
if (CDROM_IRQFLAG /= "00000" and CDROM_IRQFLAG /= "00001") then
pendingDriveIRQ <= CDROM_IRQFLAG;
end if;
CDROM_IRQFLAG <= "00001";
if (CDROM_IRQENA(0) = '1') then
irqOut <= '1';
end if;
ackRead_valid <= '1';
end if;
end if;
end if;
if (ackPendingIRQNext = '1') then
@@ -1105,11 +1112,11 @@ begin
workCommand <= nextCmd;
cmdResetXa <= '1';
if (driveState = DRIVE_READING or driveState = DRIVE_PLAYING) then
-- todo: should this be swapped between single speed and double speed? DuckStation has double speed longer and psx spx doc has single speed being longer
-- Matches psx spx doc and DuckStation
if (modeReg(7) = '1') then
workDelay <= 2157295 + driveDelay; -- value from psx spx doc
else
workDelay <= 1066874 + driveDelay; -- value from psx spx doc
else
workDelay <= 2157295 + driveDelay; -- value from psx spx doc
end if;
end if;
if (driveState = DRIVE_SEEKLOGICAL or driveState = DRIVE_SEEKPHYSICAL or driveState = DRIVE_SEEKIMPLICIT) then
@@ -1915,9 +1922,13 @@ begin
ackDriveEnd <= '1';
else
skipreading := '0';
if (setLocActive = '1' and (currentLBA - seekLBA) >= 2) then
skipreading := '1';
end if;
-- optional fix for Dave Mirra / Trasher
if (backwardSeekHack = '1') then
if (setLocActive = '1' and (currentLBA - seekLBA) >= 2) then
skipreading := '1';
end if;
end if;
if (isAudio = '1') then
if (currentTrackBCD = x"00") then -- auto find track number from subheader
currentTrackBCD <= nextSubdata(1);
@@ -2817,19 +2828,23 @@ begin
case (copyState) is
when COPY_IDLE =>
if (copyData = '1' and ce = '1') then
if (copyData = '1' and ce = '1' and
sectorBufferSizes(to_integer(readSectorPointer)) /= 0) then
copyState <= COPY_FIRST;
copyCount <= 0;
copyReadAddr <= 0;
copyByteCnt <= 0;
copySectorPointer <= readSectorPointer;
sectorBufferSizes(to_integer(readSectorPointer)) <= 0;
if (sectorBufferSizes(to_integer(readSectorPointer)) = 0) then
copySize <= RAW_SECTOR_OUTPUT_SIZE / 4;
else
copySize <= sectorBufferSizes(to_integer(readSectorPointer));
end if;
-- read size before clearing buffer size
if (sectorBufferSizes(to_integer(readSectorPointer)) = 0) then
copySize <= RAW_SECTOR_OUTPUT_SIZE / 4;
else
copySize <= sectorBufferSizes(to_integer(readSectorPointer));
end if;
-- clear buffer size after size was latched
sectorBufferSizes(to_integer(readSectorPointer)) <= 0;
end if;
when COPY_FIRST =>
copyState <= COPY_DATA;

2
rtl/psx_mister.vhd
View File

@@ -66,6 +66,7 @@ entity psx_mister is
REPRODUCIBLESPUDMA : in std_logic;
WIDESCREEN : in std_logic_vector(1 downto 0);
oldGPU : in std_logic;
backwardSeekHack : in std_logic;
-- RAM/BIOS interface
biosregion : in std_logic_vector(1 downto 0);
ram_refresh : out std_logic;
@@ -359,6 +360,7 @@ begin
REPRODUCIBLESPUDMA => REPRODUCIBLESPUDMA,
WIDESCREEN => WIDESCREEN,
oldGPU => oldGPU,
backwardSeekHack => backwardSeekHack,
-- RAM/BIOS interface
biosregion => biosregion,
ram_refresh => ram_refresh,

3
rtl/psx_top.vhd
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@@ -70,6 +70,7 @@ entity psx_top is
REPRODUCIBLESPUDMA : in std_logic;
WIDESCREEN : in std_logic_vector(1 downto 0);
oldGPU : in std_logic;
backwardSeekHack : in std_logic;
-- RAM/BIOS interface
biosregion : in std_logic_vector(1 downto 0);
ram_refresh : out std_logic;
@@ -1404,6 +1405,8 @@ begin
LIDopen => LIDopen,
region => region,
region_out => region_out,
backwardSeekHack => backwardSeekHack,
pauseCD => pauseCD,
Pause_idle_cd => Pause_idle_cd,