Search found 52 matches

by AmiDog
August 4th, 2016, 8:46 pm
Forum: Hardware
Topic: SCPH-7502 = Better graphics ? ("PS1.2")
Replies: 20
Views: 24945

Re: SCPH-7502 = Better graphics ? ("PS1.2")

The old GPU only use 5 bits when modulating the texture color while the new GPU uses all 8 bits. That might explain the banding. You can test the difference with my GPU plugin. It's also documented on my wiki.
by AmiDog
March 5th, 2016, 9:58 pm
Forum: Homebrew (General)
Topic: Tajmiing
Replies: 6
Views: 5233

Re: Tajmiing

I've uploaded a version of the demo which also works on NTSC units. Also made a capture and uploaded to youtube.
by AmiDog
March 4th, 2016, 8:51 pm
Forum: Programming/CPU
Topic: how to use the CPU 4k cache?
Replies: 6
Views: 5193

Re: how to use the CPU 4k cache?

The CPU doesn't have a data cache as the 1k which could be used as a data cache is used as scratchpad. It's easy to verify. It might be possible to put the data cache in normal mode (haven't tested that yet), but it would still only be 1k. The CPU has a 4k instruction cache though (which is automati...
by AmiDog
March 3rd, 2016, 7:02 pm
Forum: Programming/CPU
Topic: how to use the CPU 4k cache?
Replies: 6
Views: 5193

Re: how to use the CPU 4k cache?

Not sure what he means, but the CPU doesn't have a data cache. And the GPU has its own memory. Doing DMA from system memory to video memory might be faster if the CPU doesn't access memory at the same time, unless the CPU is halted during DMA anyway...
by AmiDog
March 1st, 2016, 12:35 am
Forum: Homebrew (General)
Topic: Tajmiing
Replies: 6
Views: 5233

Re: Tajmiing

Yes, it's PAL only for now. I'll fix that as soon as I can. The calibration measures the number of CPU clocks per rasterline. It's a fractional number, and to be able to do any kind of timing sensitive effects I need to adjust my timing each rasterline based on that number. You will get the warning ...
by AmiDog
February 16th, 2016, 11:21 pm
Forum: Homebrew (General)
Topic: Tajmiing
Replies: 6
Views: 5233

Tajmiing

hr Tajmiing hr Username: AmiDog Project Title: Tajmiing Time to Complete: Too much :-) SDK: None Genre: Demo Latest Release: Version 1.1 In Development: No Initial Release Date: 14-FEBRUARY-2016 Last Date Updated: 03-MARCH-2016 Controller: None Players: 1 Memory Card: 0 Block Languages: Eng Region:...
by AmiDog
November 13th, 2015, 2:00 am
Forum: Members Downloads
Topic: MCLaunch 1.0 - Memory Card PS-X EXE launcher
Replies: 26
Views: 29766

Re: MCLaunch 1.0 - Memory Card PS-X EXE launcher

I'm going to create a few tests to be sure. However, just had a look at the Blade Lib, and it does something similar to what I was doing: #define gp0 (*(vptr)0x1f801810) #define gp1 (*(vptr)0x1f801814) void GP_SendGPU0(u_long gpu_primitive) { gp0 = gpu_primitive; } ... gp1 = 0x01000000; // reset the...
by AmiDog
November 12th, 2015, 8:08 pm
Forum: Members Downloads
Topic: MCLaunch 1.0 - Memory Card PS-X EXE launcher
Replies: 26
Views: 29766

Re: MCLaunch 1.0 - Memory Card PS-X EXE launcher

I can confirm that it wasn't a problem with MCLaunch. After spending way too much time trying to locate the offending piece of code, one of the problems turned out to be code like this: #define GPU_DATA_ADDR (0x1f801810) #define GPU_CONTROL_ADDR (0x1f801814) #define GPU_DATA *((volatile u32 *)GPU_DA...
by AmiDog
November 10th, 2015, 7:25 pm
Forum: Members Downloads
Topic: MCLaunch 1.0 - Memory Card PS-X EXE launcher
Replies: 26
Views: 29766

Re: MCLaunch 1.0 - Memory Card PS-X EXE launcher

I made a few tests yesterday, starting with the smallest assembly program possible which just rendered a single primitive. That worked. I then began extending it, made it larger by inserting lots of nops etc. And then I started copying various pieces of code from the tests which failed. The first pi...
by AmiDog
November 9th, 2015, 10:27 pm
Forum: Members Downloads
Topic: MCLaunch 1.0 - Memory Card PS-X EXE launcher
Replies: 26
Views: 29766

Re: MCLaunch 1.0 - Memory Card PS-X EXE launcher

Thanks for the sources. Had a quick look but didn't see anything obvious. These lines are rather interesting though:

char *ProgramPointer;

if(RunExeFlag) goto *ProgramPointer;

Didn't know you could do it like that. (I'm using function pointers to handle similar situations.)
by AmiDog
November 8th, 2015, 12:46 am
Forum: Members Downloads
Topic: MCLaunch 1.0 - Memory Card PS-X EXE launcher
Replies: 26
Views: 29766

Re: MCLaunch 1.0 - Memory Card PS-X EXE launcher

I've been using MCLaunch to test a few things on a chipped PSOne, which works great. However, I'm unable to get things to work on a chipped PS2. MCLaunch seems to work fine. It boots, finds files on the memory card and begins loading. After a while the screen then turns black and nothing happends. I...
by AmiDog
September 16th, 2015, 9:49 pm
Forum: Input/Output
Topic: PS1 and PS2 memory card
Replies: 1
Views: 2173

PS1 and PS2 memory card

I know that the PS1 has no MagicGate support and thus can't read/write PS2 saves. However, is MagicGate required to access the card at all, or could one write non-encrypted files to a PS2 memory card, and access them from a PS1?
by AmiDog
November 5th, 2014, 8:42 pm
Forum: Research
Topic: Playstation CPU reversing [56k Warning]
Replies: 67
Views: 66214

Re: Playstation CPU reversing [56k warning]

Akari wrote:Real numbers used for YUVtoRGB conversion are:

Code: Select all

G=(-88/256 * B)+(-311/256 * R)
R=(359/256 * R)
B=(454/256 * B)
Are you sure? That G formula doesn't look correct to me. According to the tests I ran a year or two ago on my SCPH 7002 unit, it should be:

G=(-88/256 * B)+(-183/256 * R)
by AmiDog
October 24th, 2014, 12:52 am
Forum: Graphics/GPU
Topic: I present, Sir. Oinks-A-Lot
Replies: 1
Views: 2205

Re: I present, Sir. Oinks-A-Lot

Cute! Me likes :-)
by AmiDog
August 15th, 2014, 10:14 pm
Forum: Graphics/GPU
Topic: What rasterization algorithm does the PSX use?
Replies: 3
Views: 3919

Re: What rasterization algorithm does the PSX use?

I don't know what the PSX does in hardware, but I think someone have decaped a PSX GPU and taken photos of the die, so we might find out sooner or later. But whatever algorithm it uses, it produce a "perfect" result. That is, you either need to compute the x coordinates using divides each row, or us...
by AmiDog
August 11th, 2014, 11:38 pm
Forum: Graphics/GPU
Topic: What rasterization algorithm does the PSX use?
Replies: 3
Views: 3919

Re: What rasterization algorithm does the PSX use?

Yes, the PSX doesn't render quads, even though people still like to call them that, but rather triangle strips with 4 vertices. Other than that, the PSX doesn't render the rightmost pixel or bottom row of the triangle, and the way the triangle is rendered (in one or two passes, and the direction of ...
by AmiDog
August 5th, 2014, 6:35 am
Forum: Graphics/GPU
Topic: What happens when you write to GP0 when the GPU is busy?
Replies: 2
Views: 2706

Re: What happens when you write to GP0 when the GPU is busy?

First of all, there is a 16-word command buffer, so it's always safe to write 16 values to GP0. The GPU will fetch commands from the buffer until it's empty. However, the GPU is a superscalar design, which make things somewhat more interesting. It seems to be able to fetch and process up to two comm...
by AmiDog
May 28th, 2014, 5:49 pm
Forum: Research
Topic: How to disassemlbe/edit PSX BIOS ?
Replies: 12
Views: 11537

Re: How to disassemlbe/edit PSX BIOS ?

a4451137 wrote:So many years and no one hack it :D
Well, nocash (martin korth) has written a complete BIOS clone for his emulator, so he has probably spent some time hacking the original BIOS.
by AmiDog
May 20th, 2014, 11:16 pm
Forum: Programming/CPU
Topic: Testing interlaced code; no real hardware to hand
Replies: 15
Views: 14855

Re: Testing interlaced code; no real hardware to hand

I can confirm that it's indeed possible to force the GPU to render odd or even rows during vblank. However, changes to the display offset doesn't have any affect until bit31 changes, which it does once per rasterline, so one better busy-wait until it has changed to the desired state, or one will end...
by AmiDog
May 19th, 2014, 6:41 pm
Forum: Miscellaneous / Off Topic
Topic: A noobie question
Replies: 9
Views: 8361

Re: A noobie question

Samkrfc wrote:Hello everyone, I've been looking into PS1 homebrew and I've been wondering, will I be able to play PS1 homebrew on the PS3?
If your PS3 is running a custom firmware, than probably yes. If it's running the official one, then no... In any case, if it works, it'll be using Sonys crappy PS1 emulator.