PS Hard Disk Drive

It's not possible. First off, the Xploder/Xplorer doesn't *have* any RAM to speak of; it just provides access to the PSX's memory. Any executables you send from the PC are loaded into the 2MB main memory. Second, even if you would add RAM to the cart (which would entail significant rewiring and additional circuitry), the PSX PIO bus only has, if memory serves, 24 address lines, meaning it can access a 16MB address space at most. Seeing as that includes the cartridge's registers, ROM and everything you'd probably hit the wall at 8 meg.

 

Might be able to get away with banking it but then you'd not have access to 100% of the RAM at any one moment. Might defeat the whole purpose unless that isn't a problem.

 

Hmm, I was thinking of 'steaming' a game to the PS.

So eventually, an (.ISO or whatever file) could be sent to the Xplorer, the Xplorer de-codes it and send it as bits or bytes to the PS RAM. A CD-ROM programed however, would enable code to be executed to load the data from the RAM to be processed.

It would happen so fast, that the 2MB of RAM would not be able to fill up fast enough. Because as soon as that data is in the RAM, it would get processed.


I dunno. I am just making up theory's as I go along


Another option, is to de-solder the 2 MB RAM on the PS and upgrade it to whatever. Lets say 16 MB...

Unless putting the game into RAM is useless, how else can I have it executed on the PlayStation (natively like the CD-ROM). Would I have the CPU-R3000 take it from the PIO > Xplorer > Cable > PC and 'decode' it as streaming data like the CD-ROM??

IE: Virtual CD-ROM acting as code???

Or what would you guys recommend??

 

People have already done this, the problem is it's slow and you don't get red book audio.

If you want to try it then just patch the cd code in ram with code that communicates over the xplorer PIO. It shouldn't be too hard to get something up and running.

 

That just happens on the filesystem level, right? Like Caetla with pcdrv:\ support?

Indeed, that way you won't get audio (CDDA or XA), nor would you - normally - get past copy protection. I think the only way to get around the audio issue is patching the code, since I'm pretty sure the Sony libs communicate directly with the CD controller. Doable, but not a 100% transparent solution unless you feel like replacing the CD controller (only possible on the earliest revisions). Or you should put up with the AR's presence and the lack of audio.

As for upgrading the PS RAM, that has been done succesfully, but I lost the source.

 

Ah ok. Thank you.

Are you sure you can not relocate the source for me? Only if it is not to much trouble for you.

I have been messing with sending more executable's at this stage.

Also got codewarrior installed from the PSY-Q kit...

 

PSY-Q is for yaroze isnt it?

If its the one I am thinking of it compiles ECOFF's, not EXE's, so you will need to load LIBPS to the PSX ram so make it work.

 

Lol. I dunno. But when I tried to compile, it gave me an error for not finding a file with the #include code. Can't be bothered to start it up and look, but it was a 'something'.h file...


What program / compiler would you recommend?

 

Sorry wrong way round..

replace PSYQ with Codewarrior....

 

OK you lost me.

So, use Codewarrior to program .EXE's?

CW is for Yaroze...

Can you give me some info just in a nutshell for me??

Much appreciated :dance:

 

Bascially just stay away from Codewarrior and focus on PsyQ if you can.

Codewarrior is more high level stuff aimed at people making games on the Yaroze whereas PsyQ was a full on after market dev kit and used by many many studios as it was cheap but powerful.

 

Ah, ok. ray:

PSY-Q was also made by Psygnosis right?

What compiler do I use for it, what do I write the code in??

Just in a nutshell if you can, or link me please

 

I think I owe you an apology Calpis. A PM was sent with a sincere apology.

I am sorry. ;-)

 

I believe there was an iso loader as well, however that can't do audio for the same reason: The red book audio goes straight to the sound chip. Unless you put some hardware between the laser and the motherboard there is basically nothing you can do about this. That would be what I'd do, if I had the time.

 

Yea, I think I will have to change plans and go through the laser system.

I don't think I can figure out the pinouts on a PSone for a PIO port. I know someone did it with the SIO but that is not as useful.


I don't know about the laser assembly;
Thats a lot more now in the hardware area.


Now im really confused what to do

Maybe I will get the PIO port going with streaming an .iso (or whatever file) for now. If I make a custom ROM (somehow), to tell the Xplorer where to send that data then that may be an option.

I still have to think around all this.

I mean I could stream into the VRAM and then move it to the RAM. The VRAM is faster then the 2 MB RAM. But the thing is, the RAM and VRAM will be constantly hammered with all that data when the RAM and VRAM is needed for games especially like Crash Bandicoot.

Nope. Not going to work.

I need to see if the PIO port has access to the CXD2938Q ('IC 732) processor. From memory, I think that was the IC that handled the CD-ROM processing. Then the 'IC 304' and the 'IC 702'. Though, 'IC 722' only handled the motor.

I will look into it.

Give me a day or two :thumbsup:

 

Erm how about every game. Ever.

I don't think you'll be able to hijack the address space of other chips as a way of "streaming" in data from an ISO, it'll just be far too complicated and the timing to ensure that you're not interrupting a process would take you hundreds of years* and you'd need a custom boot loader for every game.

You will have to build a custom device to hold whatever you program to communicate with the laser input I don't think there's anyway around it. You can't have a program that intelligently trickles raw CD data through available space in the existing hardware.

If you can somehow send it to the hardware that handles data taken from the laser then you are on to something but it's going to take some seriously good low level coding.

I'm by no means an expert on any of this and I was slating you a few pages back for simply not having a clue. I can see how seriously you're taking this so I'll stick with it but I still think you're a long long way off.

I also think you're going to need way more than an Xplorer cart. They're good but I don't think they're going to give you the results you need. You'll need some good hardware to understand what is going in and out of what and precisely when.

*Not being sarcastic here...it really would.

 

I understand. But I wont give up :thumbsup:

I realised the other day that there is no way I can use the RAM as a place to stream the data...

I can only do this, if I have access form the PIO to the CD-ROM controller. But, it is better to go by hardware.

(especially games like Crash Bandicoot as they used custom library's that they edited to make all there data fit into the RAM, unlike many other games.)


What I will finish off first I guess, is the Slot Loading Drive. That will get me going again in the hardware side and take me off on my previous work. It will also make me a lot more familiar with the CD-ROM controller and all...


Thanks for the support.


Like someone mentioned above, this is all just wasted keystrokes at this point...

 

I understand. But I wont give up :thumbsup:

I realised the other day that there is no way I can use the RAM as a place to stream the data...

I can only do this, if I have access form the PIO to the CD-ROM controller. But, it is better to go by hardware.

(especially games like Crash Bandicoot as they used custom library's that they edited to make all there data fit into the RAM, unlike many other games.)


What I will finish off first I guess, is the Slot Loading Drive. That will get me going again in the hardware side and take me off on my previous work. It will also make me a lot more familiar with the CD-ROM controller and all...


Thanks for the support.

 

Really? I've never seen that... would be most interesting to look at. Do you have more info?

 

Well I can not do anything until I get an FPGA development kit (Altera DE2) to get started.

I was going to intercept the data lines on the CXD2938Q and see what I can do with them to make a IDE solution on the FPGA (emulate the CD-ROM or make another CD-ROM drive work).


The Sony CXD2938Q has been used in arcade game boards such as, Gamshara, Mr. Driller 2 and Mr. Driller G that all ran on the Namco System10. However, I believe the chip was rebuilt without a CD DSP, Digital Servo and CD ROM Decoder. It only contained the SPU.

I will by pass the Mechanism Control (IC-732), the RF AMP (IC-723) and the Focus / Tracking / Coil Drive / Motor Drive. These are all useless and are contained on the 'tray' or 'slot loading' CD-ROM drive I want to use. Either through the IDE protocol or a custom way.


Does anyone have an Altera DE2 development board I can buy or borrow from them with a deposit? ;-)