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CPC Plus cartridge replacement : one more

Started by gerald, 16:39, 01 November 14

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0 Members and 2 Guests are viewing this topic.

Are you interested in buying a 3D-printed case for the cartridge? Hoe many units? (only vote if you want one or more!)

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Total Members Voted: 209

arnoldemu

Quote from: TFM on 20:32, 03 March 15
The greatest thing about this project is that we now REALLY can start do develop for Plus Cartridges. No offense against the great Plus emulators out there, but the real machine is the real thing.  :)

*start* developing? I think you mean that this project is perfect for showing off a completed game that is already in development?
My games. My Games
My website with coding examples: Unofficial Amstrad WWW Resource

XyphoesRe

Are there GX4000 Cartridge Cases planned yet? As my company is doing some plastic molding projects in greece later this year i can try to check out what the molds will cost and to make some cartridge cases for teh GX4000 and CPCplus wich are a bit longer (about 10mm) so more additional hardware can be build into the case.


skywalky


TFM

Quote from: arnoldemu on 10:08, 04 March 15
*start* developing? I think you mean that this project is perfect for showing off a completed game that is already in development?


For some games you're right. Maybe even most. But even if the emulation of the CPC is pretty perfect in this days; the emulation of the Plus lacks a lot of fine tuning. I talk about all the Memory Mapped stuff. Emulators in some regard act quite different than the real machine.


So... I just don't want to burn an EPROM each time I want to test it on the real machine.  ;)
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

TFM

Quote from: XyphoesRe on 12:28, 04 March 15
Are there GX4000 Cartridge Cases planned yet? As my company is doing some plastic molding projects in greece later this year i can try to check out what the molds will cost and to make some cartridge cases for teh GX4000 and CPCplus wich are a bit longer (about 10mm) so more additional hardware can be build into the case.


Well quite a while ago I talked about Cartridge molding with BluesBrothers... sadly they are not made up to now. What I would need is 100 Cartridges (regular size). If this helps you to reduce pricing, just let me know.  :)  Or PM me if you like.  :)
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

The Last Bandit

Molded case would be nice but the tooling will cost a fortune. Rough estimate on a chinese site suggest the tooling cost alone is over $2K that's assuming a single mold is required i.e. symmetrical parts (which they're probably not).


3D printed parts may be more cost effective if a bit uglier..

TFM

If they are stable enough, than that's fine. For Cart's in general and for Geralds Super-Cart here.


So does Geralds Cart fit in a regular Cart shell? If I read the posts here then yes.... We could get quite a good number together so the single unit can get cheaper.



TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

gerald

Quote from: TFM on 19:16, 04 March 15
So does Geralds Cart fit in a regular Cart shell? If I read the posts here then yes....
It fits in a regular Cart shell, and this was the number 1 on the specification list !

andycadley

Quote from: gerald on 22:29, 02 March 15
I still need to do some tests on a non-visible part of the uC code, namely functions that will allow code on the CPC to access the sD filesystem (fopen/fread/fclose equivalent). These will be read only at relase, but later update may give write access.
Looks good. Does the ability to write to the cartridge place any limitations on how you can write code? Specifically is there anything which should be avoided to prevent accidentally triggering this?

gerald

Quote from: andycadley on 20:18, 04 March 15
Looks good. Does the ability to write to the cartridge place any limitations on how you can write code? Specifically is there anything which should be avoided to prevent accidentally triggering this?
Write access will be through command send to the uC. Command requires a specific sequence of read to different banks.
As such, it will be unlikely that a valid write command with proper parameters can be issued by accident.
But if your code has support for these commands, there is no way to prevent a crashed code to accidentally write to the card.
The only solution would be to have a write protection option associated with the cartridge.

TFM

Oh, well, guess we can take the risk. I mean... the hardware can't be destructed by the software, in the worst case just kind of getting formatted. So back to the PC and put your backup back in place.  ;) :laugh: :)
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

andycadley

Quote from: gerald on 20:59, 04 March 15
Write access will be through command send to the uC. Command requires a specific sequence of read to different banks.
As such, it will be unlikely that a valid write command with proper parameters can be issued by accident.
But if your code has support for these commands, there is no way to prevent a crashed code to accidentally write to the card.
The only solution would be to have a write protection option associated with the cartridge.
That's fair enough and the kind of thing we can undoubtedly avoid.

Guy0me

Wow this is great !  :D If it works one day, it's a hell of a project ! I pay you to have one of this !

Shining

So writing savegame or writing highscore to cartridge should be makable, am I right ?


Another thing I've had in mind:
As I understood the internals of the CPC right, the GateArray slows the Z80 down coz of its own ram-access. So when a game runs partly in ROM (like cartridge) it could get a little speedup for complex calculations.




TGS is back

Download my productions at:
cpc.scifinet.org

McKlain

Can you run code and load data from rom without copying it to ram first?

gerald

Quote from: Shining on 15:21, 13 March 15
So writing savegame or writing highscore to cartridge should be makable, am I right ?
Yes, that the target of the write support, but the initial release will be read only.

Quote from: Shining on 15:21, 13 March 15Another thing I've had in mind:
As I understood the internals of the CPC right, the GateArray slows the Z80 down coz of its own ram-access. So when a game runs partly in ROM (like cartridge) it could get a little speedup for complex calculations.
Sadly not, ROM/RAM all share the same bus constraint.

gerald

Quote from: McKlain on 15:38, 13 March 15
Can you run code and load data from rom without copying it to ram first?
I am not sure i get your question. Which code / rom /ram are we talking about  ???

McKlain

Bear with me, as my technical knowledge is limited  ;D


What I mean is if a cartridge behaves just like another storage medium (tape, disc) in wich you have to load a program to ram to run it or you can just run your code (or access other data) from the cartridge as if it were in ram already.

gerald

#243
Quote from: McKlain on 15:56, 13 March 15
Bear with me, as my technical knowledge is limited  ;D


What I mean is if a cartridge behaves just like another storage medium (tape, disc) in wich you have to load a program to ram to run it or you can just run your code (or access other data) from the cartridge as if it were in ram already.
The main purpose of the cardrige is to replace the ROM. Using it as replacement for a tape/disc, while doable may not be the easy or practical.

Let explain why :
The cartridge is seen by the CPC as a ROM, and only a ROM (read only).
Communication with the microcontroller is done using a sequence of read to ROM area that pass a command, which is then executed by the microcontroller.
On its side, the microcontroler only see the RAM that emulate the ROM on the CPC. That mean that all answer from the microcontroler has to go in this ROM. And while the microcontroler has control over the RAM, the CPC cannot read anymore from the ROM.

So, to read a file, the CPC has to order the microcontroler to read that file, wait for completion, then move it to the RAM to mimic a tape/disk load. Slow, but acceptable.

To write, the cpc will have to send a command and then provide the data using the same mechanism which is really slower.

In any case, a X-MASS or symbiface would perform better from a throughput point of view. But being able to save on a GX4000 is nice ;)


Now, nothing prevent you to load a piece of code/data in rom and use it from there. In fact, this is the main goal of the file access commands.

TFM

Great thing is: We can SAVE high-scores that way too.  ;)
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

seanb

That depends on If I can actually make it onto the high scores table.
Thou shall not question Captain Wrong!

TFM

TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

Apollo

Aaah, really looking forward to this one! Finally some catridge to code for the plus  ;D
CPC - My beloved first computer!

gerald

Everything has to come to an end.

And I have no reason to make you wait any further  :D

So, I am about to make the cartridge emulator available to people that showed their interest in this thread. I will contact them by PM in 1st come / 1st served order.
The kit (cartridge + uSD + SD adapter) will cost 60 euros + shipping (1.55 for france, 4.7 for europe).

You will find more details on the page dedicated to C4CPC

Munchausen

Wow, we really are spoiled with CPC hardware these days!

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