If the card doesn't have the system 3.0 bios on it, then that means you have to swap cards when you want to play normal CD/SCD games. Or, make the card in such a way that it only works with Duo or SuperCDROM units.
Yep, the 1MB RAM approach would only work on DUOs and SuperCDROM.
It's a limitation ... but it would make it both cheap and producible without infringing anyone's copyright.
The TED v2 is a "better" solution in every way ... and definitely my "preferred" one, but there is the question of price.
Now it seems like a reasonable price for what it offers to me ... but YMMV.
If using the original bios is an issue, then a brand new bios could be made. Game Express did it, and they used the standard CDFS boot sector approach too (not needed but interesting anyway). We already pretty much know how to access and interface with the hardware directly, because of emulators.
That's a great solution ... but someone has to write it, and it can't be like the cutdown Game Express one if you want to make it compatible with System Card 3 games so that it can run translations.
The idea was to make translator's lives easier, not to make them swap out every CD BIOS call to work with a new BIOS.
Now, for newly-written homebrew, you can do whatever you like.
I'll be completely honest; at this point I don't see using the original bios image as an issue. From the point of view of homebrew, CD games already contain the infringing security string of text. So there's already an infringement right there. I know it's nice to be closer in the clear than in the grey, or clearly in the wrong, but I don't know if it's worth the effort.
If you're willing to manufacture new System Card 4 carts for people to buy that contain Hudson's BIOS, or contain your own replacement BIOS, then that's great!
I honestly think the most important thing is to have a standard layout that can be used by multiple cards out there already,
Yep, totally agree.
and people could assemble the card themselves (DIY). That way, more than one source and flavor exists that's compatible between them all. And if it's simple enough, people can also assembler their own cards (pcb, rom, ram, solder skills, etc). 512k rom with 512k ram works for me, but the idea of wasting that upper 256k rom nags at me. 256k rom + 768k ram is better.
That's where you start to lose me. I just don't think that most game players are going to want to spend $1000 or so on all the items that they'll need to manufacture a $20 System Card 4.
Of those people that do, not all will be willing to advertise/sell a cart that uses a stolen BIOS, and that would that open them and their family up to litigation.
IIRC, this thread started with the dream of producing a cheap System Card that would give translators a bit of extra memory to make their lives easier and encourage translations.
Going up to 768KB RAM just isn't needed for that ... but you'd get it anyway with the 1MB-RAM card (or the TED v2).
When you're talking about homebrew development ... then the-sky's-the-limit.
But unless you want to sell a custom cart with every CD and have $100-plus homebrew games, then you might as well just aim for TED v2. At least they're going to be available, and they can also play HuCards.
Once they're not available anymore, then you can just clone KRIKzz's memory map (which I believe is just the Street Fighter II mapper with all RAM).
My idea of putting 1MB of RAM in a cart was mainly so that it could also play the entire HuCard library cheaply. That would actually give people a reason to buy one.
If people don't want that, then TailChao has already suggested just doing a 256KB add-on cartridge that would work with any DUO or SuperCDROM, and not require any software or CD swapping at all.
It would be transparent to any existing game, and only show up to a game that checked for memory in the $80000-$BFFFF region.
It's still 2 chips, a 256KBx16 SRAM and a 74HC138 decoder, and it's $3.00 cheaper in parts (so $3.60 plus decoupling caps plus board).
It would be compatible with TED v2 and the CD StupidCard, so it's not making the landscape any messier.
That's probably the best option for translations ... but I'd be surprised if anybody would buy one until there are translations that need it.
I could make the Xanadu translations require extra memory in order to create a market ... and it would definitely make my job easier. But that doesn't seem like a nice thing to do, even if it might slightly lower the chance of a PCEWorks boxed-set.
On a DIY card, a simple mapper could be made by doing a read ( or read. whichever's easier) at external address $000000 (each time flips the active line to either the lower rom or lower ram; you'll have to keep track yourself. I'd personally map it once and leave it).
It's easy to make things as complex as you like if you're willing to make people buy/use a CPLD programmer on top of everything else.
I was trying to keep things as simple as possible so that it's easy to make (or preferably get cheaply contract-manufactured in China).
But here's the most important thing that bothers me... no software. There's no software, that I know of publicly, that's creating a demand for this new system card. And without that demand, only the few diehards are going to bother with it.
Yep, that's the big issue.
There's no
need for a "System Card 4" yet, and until something with extra RAM is available, then any translation that needs more memory is going to limited to running in Mednafen, or with a TED v2.
That's why I thought the 1MB RAM cart made at least a
tiny bit of sense ... you can actually do something useful with it.
That's why I was hoping the TED 2.x would hurry up and get here. The CD StupidCard is viable, but not accessible right now. Things could be prototyped and shown on the new TED to garnish interests in such upgrades. I have a few things that are essentially waiting for new TED to arrive (because people are opt to buy it anyway). Basically show off stuffs and generate interest (i.e. have it available to the public; something tangible in their hands. d/dx) .
Am I close to the mark here or am I off in lala-land?
Nope, I think that you're pretty much right-on.
At this point, anyone that wants extra RAM should make sure that their stuff runs on the TED v2.
When there's actually a
need for a cheaper alternative, then someone can make one, with whatever design they believe make sense.
[EDIT]
Oh, BTW ... I just realized that it would be pretty easy to create a generic patch program that would add the CD BIOS to a translation's ISO before you burn it so that it would run on the 1MB-RAM cart without any CD-swapping. You'd just expand the patched-game's ISO track by another 256KB.