CD Stupid Card 4.0

[SkyeWelse]

Thank you for clarifying that Elmer. That makes sense to me. It would likely have to be in the hands of developers for awhile before any real decisions or processes would be made as to whether the card would be required or not.

And if that's the case, perhaps there would be enough support at that time for TailChao to make another batch. I'm definitely considering getting a Turbo EverDrive 2.0 at the very least. I'm trying to follow along with what SamIAm mentioned in the post directly after yours about the Stupid Card 4.0 and EverDrive 2.0 being compatible, but I'm a bit lost on that since you could only have one card inserted in the HuCard bay at one time right? Unless there is a slot expander hardware that I don't know about. I may be over thinking things here... but it I'm trying to get on the same page as the rest of you.

-Thomas

[SamIAm]

I mean that it would be nice if people could use a Turbo Everdrive 2.0 instead of the Stupid Card 4.0, not both of them together. In other words, if you bought an Everdrive, you wouldn't have to also buy the 4.0 card to play the translations or homebrew games that are made for it.

Both cards are hooking up a huge chunk of RAM to the system through the hucard port. However, if they are designed too differently, it might not be possible for hackers/developers to use that RAM in the same way for each card.

[elmer]

I mean that it would be nice if people could use a Turbo Everdrive 2.0 instead of the Stupid Card 4.0, not both of them together. In other words, if you bought an Everdrive, you wouldn't have to also buy the 4.0 card to play the translations or homebrew games that are made for it.

Remember ... we still don't know yet if the TED2's RAM will be CPU-writable. For me, that's the big question.

His primary audience is obviously people that are playing HuCard images.

So we can be 99.9% sure that it will be able to do 1MB "linear" mode. But we still don't know if you'll be able to write to any of that memory.

If the translation guys stick to the Stupid Card's "linear" mode, then their stuff should be compatible with the TED2 ... that's if his memory is CPU-writable. Did I mention that we don't know about that, yet?

For any of us guys contemplating using the 2MB in "Standard Mode" ... I'd be very, very surprised indeed if the TED2 is even remotely compatible.

More likely, is that it would support the Street Fighter mapping scheme ... but (let's all stand up and say it ...) we still don't know if it's going to be CPU-writable.

If it is writable, and does support the Street Fighter mapper ... then you'll probably find that developers can make any newly written game work on either the Stupid Card, or the TED2.

It would just be a bit of a programming pain to support the TED2, Stupid Card, and possibly Arcade Card.

Would this be the time to mention my old post in the original "System Card Dreams" thread that suggested that the translators just move forward with the 1MB MCGenjin that's already supported in Mednafen ... and that the rest of us cool it a little bit until the TED2 comes out? 

Having said which ... I'd still really like one of these for development, whatever happens with the TED2. Combine the Stupid Card with a USB-based Develo-board and you've got a really nice development system.

[SamIAm]

Yeah, the whole idea is to make things easier for hackers/developers, so I wouldn't want to defeat that by asking them to take extra time and make custom versions for both the TED2.0 and the Stupid Card.

Still, as soon as the time is right, somebody should really contact krikzz with details about the Stupid Card. You can be sure that he is working on finalizing the TED2.0 right now, so it's a really good time to let him know.

[shubibiman]

Whatever comes out of this will be good. I can't wait to see it happen and then being used for homebrew.

[elmer]

Still, as soon as the time is right, somebody should really contact krikzz with details about the Stupid Card. You can be sure that he is working on finalizing the TED2.0 right now, so it's a really good time to let him know.

I've just posted there to see if he'll tell us his design goals ... but it doesn't mean that he'll respond.

FYI ... he posted pictures of the prototype TED2 cards a while back ...

Version 2.0, dated 2nd Oct 2014.
Version 2.1, dated 22nd Dec 2014.

It looks, to me, like they contain ...

Code: [Select]

2 x ALVC16424S 16bit 3.3V-5V transceiver
1 x 50MHz oscillator
1 x Lattice/SiliconBlue iCE40HX1K FPGA (1280 logic cells, 64Kbit embedded RAM).
1 x FTDI FT245RL USB2 to parallel FIFO (up to 1MB/sec).
1 x Micron CellularRAM PSRAM MT45W?MW16
 either ... MT45W4MW16BGX 4MBx16 (8MB)
 or ....... MT45W2MW16BGX 2MBx16 (4MB)
 or ....... MT45W1MW16BGX 1MBx16 (2MB)

That's a powerful piece of hardware!

[TailChao]

I certainly can't see why they chose to do the external mapping rather than the simple 2-level mapping that's on the Stupid Card ... nor can I see why they couldn't have chosen to do the 2-level mapping with dram.

My assumption is that the DRAM they used was actually very (s)low grade. Having access limited only to ports means that the DRAM controller has all the cycles in between the actual reads to prefetch or store data.

From what TailChao has said it's already working in Mednafen ... so "yes"

The entire feature set isn't supported (obviously, since we're still designing the card in this thread). Right now you only get 512KB ROM + 512KB RAM using the patch I supplied in the first post since there's enough overlap between the (new) MCGenjin-CD and original MCGenjin mappers.

Luckily it shouldn't be too much work to add MGCenjin-CD emulation once we're finished with the card design and verification. But I will leave that to you guys and the Mednafen author if she wishes to do so.

Having said which ... I'd still really like one of these for development, whatever happens with the TED2. Combine the Stupid Card with a USB-based Develo-board and you've got a really nice development system.

Exactly, and I'm glad someone picked up on this. While the CD Stupid Card does allow you to use it as an enhanced Super System Card 3.0, it's really just another option for developers.
No one says you have to use it as a system card, you could pull off the BIOS and replace it with something that does bitbanged comms with a PC over the controller port. Then download your test programs to the 2MB of RAM.

FYI ... he posted pictures of the prototype TED2 cards a while back ...
...
That's a powerful piece of hardware!

Yeah, once you start using lower voltage (i.e. modern) components and doing large production runs some really cool stuff can be shoved on that little HuCard form factor.
The FPGA on there is huge though. Maybe the interface will be as nice as the Everdrive N8 where there's literally a bunch of RBFs in a directory which store mapper setups. In that case Stupid Card support will be trivial.

[TailChao]

Alright everyone, we've hit our feature lock date. Now it's time for me to move on to board layout.
I'll be allocating two weeks for this, and will report progress on Mar 20, then hopefully complete the design by Mar 27.

Thanks everyone for participating in the design phase!

[elmer]

FYI ... I just got a reply from KRIKzz on his forums ...

Re: Turbo ED V2 - Questions for fan translations and homebrew.
« Reply #1 on: Today at 05:36:35 PM »
turbo-ed v2 allow to dissable write protection, so, whole onboard ram (4Mbyte)  avaialble for developers.

No info on the access method ... but I'd still put money on the Street Fighter method, which is 512KB fixed and 512KB banked. Pretty much perfect for the translators wanting a System Card 3.0 + 512KB RAM.

[SamIAm]

Splendid! The user base for RAM-expansion translations increases!

[NightWolve]

Good, as I sold mine off in hopes of significant enhancements. Redesigning the thing just for load time improvement alone wasn't worth it, so you had to figure he'd add other feature(s) at the very least to help better distinguish it from the previous model.

[TailChao]

Re: Turbo ED V2 - Questions for fan translations and homebrew.
« Reply #1 on: Today at 05:36:35 PM »
turbo-ed v2 allow to dissable write protection, so, whole onboard ram (4Mbyte)  avaialble for developers.

No info on the access method ... but I'd still put money on the Street Fighter method, which is 512KB fixed and 512KB banked. Pretty much perfect for the translators wanting a System Card 3.0 + 512KB RAM.

At least we know the amount of RAM on the card, now.

Personally I'm hoping for some method to reconfigure the FPGA on his cartridge. This is provided on things like the Everdrive N8 where the SD card literally has a folder with different RBFs for different mappers. It's pretty nice for new development (not to mention improving emulation accuracy).

[TailChao]

Alright, end of the week update-
Attached is the layout status, shouldn't have any issues finishing the routing and dropping on a few more caps by the end of next week.

Edit:
-The large 39F040 is where the BIOS / Whatever ROM'd code you like will be stored. This will be socketed.
-The two LEDs on the top right of the card indicate whether the SWAP and LINEAR modes have been set to simplify debugging.

[elmer]

-The large 39F040 is where the BIOS / Whatever ROM'd code you like will be stored. This will be socketed.

Cool!

It's just crazy how the flash chip is so much larger than 2MB ram and the CPLD ... I guess that's why everyone moved to surface-mount.

Is there any chance of a ZIF socket fitting on there for the flash?

Attached is the layout status, shouldn't have any issues finishing the routing and dropping on a few more caps by the end of next week.

It's all that signal strength/coupling and power supply smoothing stuff where you totally lose me.

I'm glad that you're here to do this!   

[TailChao]

It's just crazy how the flash chip is so much larger than 2MB ram and the CPLD ... I guess that's why everyone moved to surface-mount.

Is there any chance of a ZIF socket fitting on there for the flash?

Yeah, it's pretty astonishing how much IC sizes have shrunk in the last few decades. There aren't any BGA parts on this board, either. The RAMs are only TSOPII's.
Funny thing is that if I used a smaller package for the flash it would have been way easier to route.

I'm actually not sure if there is enough clearance on the left side of the card to fit a ZIF socket which won't bonk against the card guide in every single PC-Engine variation. What I'd actually recommend is just taking a ZIF socket and then placing it in a wire-wrap socket (which have very long legs). This can then be placed in the board's normal socket and allows you to reuse the ZIF socket in other cards / projects (they're expensive, so I stopped soldering them down years ago).

It's all that signal strength/coupling and power supply smoothing stuff where you totally lose me.

Thing is that for these old machines you rarely have to worry about such things. The data speeds are too low to be super-vulnerable to interference. So what I am doing is really just a glorified connect the dots.

On some of my earlier cards, I had no proper decoupling caps at all. But they still worked.
A good rule of thumb is one small (.1uF-ish) cap per VCC pin on each IC and one larger cap (maybe 10uF) for the whole card. But I'm not going to fret over leaving out one decoupling cap if I can't fit it anywhere.