Cards Larger Than 128mb…

[johncross85]

Having trawled through a million threads trying to find a definitive and simple answer to whether the GP32 will ever be able to use cards larger than 128mb (for use on my GPAnswers website), I’ve been left wondering something similar.

The answer seems to be a resounding no because it would require a re-written BIOS and more importantly re-written versions of all the games/emulators etc. Although the BIOS is a possibility there is little chance that more than a couple of devvers would re-write their programs, thus leaving the whole idea completely impractical. Except…

There’s only really one type of program that would benefit from larger cards anyway – media players. So my hypothetical question is… would it be possible to create a media player specific firmware that supported cards larger than 128mb (I’m thinking SD cards with an adapter) and then patched versions of DivX and MP3 players to run in the firmware?

Run as part of a multi-firmware it could work quite well. Plug in your SD adapter and hold SELECT when switching on so you can select the media player firmware. When you’ve watched your movie or whatever you swap back to an ordinary SMC and start up with Euro firmware or YAFL or whatever.

J(ohn)

 

[ravuya]

My understanding of the problem was that it didn't as much originate in software so much as hardware; the 128MB+ cards have a voltage requirement that the GP32 doesn't provide.

 

[trooper]

I thought the 128mb limit was hard coded in the file system that the GP uses, If my understanding of what squidge said about the subject is correct.

A rewrite of the file system to support larger media would break all programs on the GP, So they all would have to be rewritten. The bios would have to be rewritten to support the new file system.

Sheeesh, What a mess. :blink:

Trooper

 

[GA01]

Having trawled through a million threads trying to find a definitive and simple answer to whether the GP32 will ever be able to use cards larger than 128mb (for use on my GPAnswers website), I’ve been left wondering something similar.

Like the plug . Btw, your site's coming along very nicely. Good job .

 

[johncross85]

I thought the 128mb limit was hard coded in the file system that the GP uses, If my understanding of what squidge said about the subject is correct.

A rewrite of the file system to support larger media would break all programs on the GP, So they all would have to be rewritten. The bios would have to be rewritten to support the new file system.

Sheeesh, What a mess. :blink:

Trooper

​

My understanding was that fixing the BIOS/firmware would fix the SMC access routines for loading the program - ie you could load the prog into memory. However, the programs use their own SMC access routines so once loaded wouldn't actually be able to read from the larger card unless the prog itself was fixed.

Anyone know if this is right because it's what I was planning on the site? The page is here

Cheers,

J(ohn)

 

[johncross85]

My understanding of the problem was that it didn't as much originate in software so much as hardware; the 128MB+ cards have a voltage requirement that the GP32 doesn't provide.

​

SMC cards over 128mb use 5v and so wouldn't work but SD cards use 3.3v so should work with an SD to SMC adapter. I think...

J(ohn)

 

[Squidge]

johncross85: What you are suggesting would work, yes. However, if you decided to load the media application from SMC, and then change the cards around when the program was up and running, you would not require a new bios - just a special media player that contained support for the larger media.

However, where are you going to get your adaptor from? Current SD->SMC adaptors only support upto 128mb, as there is no standard for >128mb SMCs. So your going to have to hack the adaptor too!

Just not practical, unfortunately.

 

[johncross85]

However, where are you going to get your adaptor from? Current SD->SMC adaptors only support upto 128mb, as there is no standard for >128mb SMCs. So your going to have to hack the adaptor too!

Just not practical, unfortunately.

​

Ah, now that I didn't know - so much for that idea then

Do you have objections to me quoting you on the GPAnswers site?

J(ohn)

 

[Squidge]

Quote away

 

[EvilDragon]

The only POSSIBLE way of supporting larger cards would be an adapter for an USB Card Reader. You could power the reader by using batteries (or making a Power Out mod from your GP).

Then you'd only need a driver for this and could read all kinds of different, larger cards.

 

[Squidge]

USB is slow. What we could do with is someone with both electronics and software experience, then we could slap an FPGA onto a small piece of pcb, and slide it into the smc slot, and then emulate all kinds of stuff. Since the smc interface is connected directly to the processor, we can get it to talk however we wants, or even emulate the smc standard and do multiple virtual smcs with 100% compatibility with older software

I still think thats the best way to go - supporting software could utilize an extra command which could switch between the virtual cards in software, whilst the older software would get fake "smc removed/inserted" notifications from the user pressing a button on the pcb. Would be perfect for media players, as they could seemlessly move between the virtual smcs.

 

[Jarska333]

Soo.. Where can I get me one of these?

 

[Squidge]

Well, most electronics components places will sell you some kind of fpga suited to the purpose, and I'm sure a bit of copper clad board will be suitable for putting it on to play with.

 

[johncross85]

Hey look, this is exactly what I was on about!

http://www.gp32x.de/board/index.php?showtopic=19213

J(ohn)

 

[mr.spiv]

USB is slow. What we could do with is someone with both electronics and software experience, then we could slap an FPGA onto a small piece of pcb, and slide it into the smc slot, and then emulate all kinds of stuff. Since the smc interface is connected directly to the processor, we can get it to talk however we wants, or even emulate the smc standard and do multiple virtual smcs with 100% compatibility with older software

I still think thats the best way to go - supporting software could utilize an extra command which could switch between the virtual cards in software, whilst the older software would get fake "smc removed/inserted" notifications from the user pressing a button on the pcb. Would be perfect for media players, as they could seemlessly move between the virtual smcs.

​

Soo.. when do you send me a sample card that I can write some stuff for it?
Seriously, wouldn't this be rather trivial task for a semi experienced FPGA guy?

 

[Squidge]

Yup, I'd imagine it would be fairly simple. However, my electronics lets me down, and I've already fried one gp32 blu, so I'd rather not buy another and fry that one too. Now, if someone could produce a piece of thin circuit board that would slide into the smc slot, and expose the contacts, it would be a lot easier than soldering inside the gp32.