I have obtained a working GX4000 and a couple of games, so the question is, it is possible to create new cartridges still and if so would it be worthwhile?
There are several ways of doing that but they are not easy, cheap or ideal.
1) cpcwiki see acid inside.
2) remove the rom from a burning rubber cartridge and replace it with your own rom.
3) Bryce has designed a pcb that uses a real acid chip.
4) the acid chip has been reverse engineered and details can be found in the wiki, requires a programmable chip of some sort.
The biggest hurdle to making new cartridges appears to be making the cases. ::)
I have the images of most of the carts, not sure what the copyright ramifications are but had most of them on a disk version back then.
Just found this, did it go any further?
Talk:CPC GX4000-Multi EPROM Cartridge - CPCWiki (http://www.cpcwiki.eu/index.php/Talk:CPC_GX4000-Multi_EPROM_Cartridge)
There's this too: Multi Cartridge - CPCWiki (http://www.cpcwiki.eu/index.php/Multi_Cartridge)
But this also needs to "borrow" and ACID from an original cartridge.
Bryce.
Great work !
I love this Cartridge ;)
Is there a posibility to use a bigger ROM ? ( for more apps )
I would certainly pay for one of these ready loaded
I have a 16way version designed, but I've only ever built one prototype of that. I was hoping to find some very low cost replacement for the ACID, but I haven't had any time to work on it. I also planned to make the ROMs software selectable instead of having a row of DIP switches.
Bryce.
Mr Bryce if you pursue it further you have a willing customer
Quote from: Bryce on 08:20, 03 April 13
I have a 16way version designed, but I've only ever built one prototype of that. I was hoping to find some very low cost replacement for the ACID, but I haven't had any time to work on it. I also planned to make the ROMs software selectable instead of having a row of DIP switches.
Bryce.
That sound amazing. About the ACID, just leave the socket open, people can take one of their own carts.
If you need software for the ROM/Game selection - just let me know! :) :) :)
Such a 16 shooter would be really cool! And it would IMHO cover all I need (4 is a bit tight).
Why not produce something like the Harmony Cartridge on Atari 2600 that uses an SD card to store the games?
This way, you only need one cartridge to play whatever exists (or will come!?!)
Besides this, new stuff can be developed - like plus only demos for cartridge only!
I believe Bryce can make this possible... ;D
Ooh, that'd be fantastic. Though I would bet Bryce may already have considered this.
You'd have to consider the interface that would allow you to 'download' an image to the cartridge's memory and then reboot with it. Maybe a modified OS version?
I can understand the harmony being useful on an Atari 2600 because there are 100 Trazillion games available and you could easily fill the SD card with them, but the CPC has less than 20 games on cartridge. Do you really need the extra complication / expense for that?
Bryce.
Mm, you got a point there. Still, it'd be useful if more games were ever to be released...
As usual the hardware has to be there first, then the software will follow - no question.
Quote from: TFM/FS on 01:42, 08 April 13
As usual the hardware has to be there first, then the software will follow - no question.
The hardware is already there. There are several options for DIY cartridges. It doesn't have to be a multi-cart for people to release software. And still no software has arrived.
Bryce.
Quote from: Bryce on 09:18, 08 April 13
The hardware is already there. There are several options for DIY cartridges. It doesn't have to be a multi-cart for people to release software. And still no software has arrived.
Bryce.
patience ;)
Quote from: arnoldemu on 09:20, 08 April 13
patience ;)
Well according to TFM no amount of patience will help, because an SD based Multi-Cart hasn't been produced yet, so the software will never come.
Bryce.
Quote from: Bryce on 13:13, 08 April 13
Well according to TFM no amount of patience will help, because an SD based Multi-Cart hasn't been produced yet, so the software will never come.
Bryce.
:laugh: :laugh: :laugh: :laugh: :laugh: :laugh:
Quote from: Bryce on 09:18, 08 April 13
The hardware is already there. There are several options for DIY cartridges. It doesn't have to be a multi-cart for people to release software. And still no software has arrived.
Bryce.
Sorry, but we don't even have shells for DIY Carts! In fact there is no hardware.
Oh good, it's another one of those threads now.
So, not having nice-looking shells means that people should ignore the existence of circuitry that can already achieve the same purpose as an original cartridge? Will you just say anything to avoid having to admit you said something incorrect?
There are no shells, that's a fact. And I don't want to put a sloppy platine in my computer, which pops out once a while, because it's not secured by the on / off switch. That should be understandabe - for everyone.
I edited my post to try to explain it.
Quote from: TFM/FS on 18:42, 08 April 13
There are no shells, that's a fact. And I don't want to put a sloppy platine in my computer, which pops out once a while, because it's not secured by the on / off switch. That should be understandabe - for everyone.
So use an original cart with a new EEPROM. As Bryce was saying, we already have several ways of getting code onto a plus, but still almost nobody is writing any...
Back to the discussion at hand:
Hm, colour me ignorant, people, but how exactly does the development cycle and testing cycle for an EEPROM cartridge for a GX-4000 look like?
And I'm considering GX-4000 only, because the CPC+ can use disks or tapes or a floppy emulator.
I could develop the first big chunks in an emulator, but during the second part of development I really need to test the time critical code on the console itself.
The GX-4000 has different timing because of the SCART connector, a different configuration than on the other pluses (program is started in ROM, will be mostly executed in ROM, and copying ROM code it into RAM creates redundancy which I'd like to avoid to save precious bytes).
Lastly I'd have to burn an EEPROM every single time, during testing and debugging to find the perfect on-screen timing or the hard to find bugs. And every time, I'd pull the ROM from the cartridge, erase it, press it into the EPROM programmer, burn the ROM, pull it out again, plug it into the cartridge, then firing up the GX-4000 ... rinse and repeat. The wearing off of the cartridge will be tremendous.
An SD card cartridge I would plug into the PC, and given a good toolchain it creates the ROM-file directly onto the SD card, then I'd remove the SD-card and insert it into the SD card cartridge, fire up the console and test it. Still not perfect but way, way easier.
Have I forgotten or missed something?
Edit: Yeah, I did. Not everyone wants to invest in an EEPROM programmer / eraser.
Quote from: MaV on 16:41, 09 April 13
Have I forgotten or missed something?
I use Flash ROMs (29F010) and a ZIF socket on the DIY cartridge.
This is the best solution at the moment.
Ok, Flash and ZIF socket helps with the wearing off.
I'd still like to avoid using an EEPROM programmer and its software on the PC.
Are there solutions where I can emulate a ROM chip with a socket and a lot of wires (and some electronics) going to a USB connector so that the PC delivers the bytes in realtime via USB preferably without using 3rd party software?
Another thing I forgot: The current solutions have to be pulled out of the cartridge socket if you want to change the ROM/EEPROM/Flash. So even if the ZIF socket helps with the wearing of the ROM itself, the cartridge and cartridge socket are still experiencing considerable wearing.
Quote from: MaV on 16:41, 09 April 13
I could develop the first big chunks in an emulator, but during the second part of development I really need to test the time critical code on the console itself.
The GX-4000 has different timing because of the SCART connector
As I understand it, the timing difference shouldn't actually affect anything. It seems to be just a slight adjustment so the CPU and PAL colour burst can be derived from the same clock. In terms of programming, you'll still get exactly 312*64 NOPs per frame, the difference is that a NOP will be slightly more than 1us instead of 1us exactly, but it's still within tolerances for the TV to accept it as a valid signal.
The only observable difference should be that over time, the GX4000 will be a bit behind the others. Unless you're actually bothered about "real world time", it shouldn't make any practical difference at all.
Quote from: ralferoo on 18:52, 09 April 13
The only observable difference should be that over time, the GX4000 will be a bit behind the others. Unless you're actually bothered about "real world time", it shouldn't make any practical difference at all.
Ah, thanks, ralferoo. We were talking about this already, and I remembered that despite the screen timing being within tolerance, there is a difference in "real world time". I'm trusting your opinion on the practical difference. :)
Still, testing on the real hardware a torment for both the developer and the hardware, ATM.
Quote from: ralferoo on 14:45, 09 April 13
So use an original cart with a new EEPROM. As Bryce was saying, we already have several ways of getting code onto a plus, but still almost nobody is writing any...
Never mind I already have my 100 ACID chips at home - ready to go.
And about software... yes, people talk a lot and feel so smart, but don't do anything.
@MaV: Yes, EPROM emulators exist, but they are rather expensive, even the very simple versions: Eprom Emulator Wice-M4 USB (http://www.batronix.com/versand/epromemulator/emulator.html)
At €300 you'd want to be quite serious about developing software to make it worthwhile. Of course it can be used to develop software for anything where the software is stored on ROM, not just a CPC.
Bryce.
Quote from: TFM/FS on 22:23, 09 April 13
Never mind I already have my 100 ACID chips at home - ready to go.
And about software... yes, people talk a lot and feel so smart, but don't do anything.
I will make a game for plus, but I already have 3 other games in development.
I need to finish those first.
One of them is around 90% complete now, another is 50%.
Same here ;-)