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d4s
Posts: 252/325 |
Originally posted by HyperHacker
Hm, just for the hell of it, I wonder if it's possible to have 2 expansion chips? Like SA-1 and SuperFX? 
its possible in theory, but i doubt one could benefit from it speedwise.
the memory maps of both chips are clashing.
each one monitors the adress bus to map its registers and ram to the snes' memory map.
a simple bankswitching circuit controlling each chips /RD and /WR lines could be used to switch between the chips.
one could assign image rendering tasks to the super fx, then switch over to the sa1 and process other stuff there.
both chips would notify the snes via irqs if their task is complete.
imho a cool configuration would be:
-sa1+64mbit rom+1mbit battery backed up ram
-superfx+1mbit ram, no rom
as i said above, youd basically have two independant carts wired up in parallel, theres no way to share ram or rom between the two chips.
this is highly simplified and theoretical, of course.
might not work at all and even if something like this would work, there wont be any use for it.
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HyperLamer
Posts: 5571/8210 |
Well I was mostly thinking for NES games. Emulating all the SNES expansion chips on something small enough to fit in a SNES cart (and run off its power) would be difficult anyway, but NES mappers are generally just chips that route certain address/data lines to chip selects and whatnot.
SNESwise, you might be able to make something where you can swap in whatever expansion chip you need, but it'd be a lot easier to just have one cart for each chip.
Hm, just for the hell of it, I wonder if it's possible to have 2 expansion chips? Like SA-1 and SuperFX? |
BMF98567
Posts: 964/1261 |
Seems to me that the best way would be to buy carts containing the expansion chips you expect to use (i.e. one SuperFX cart, one SuperFX 2 cart, one SDD-1 cart, etc.) and replace the ROMs with EPROM sockets. Of course, as BGNG mentioned, the routing of the address lines and such might be different between games, as well as SRAM size (or lack thereof)... |
d4s
Posts: 251/325 |
all super fx games use the same mapping.
they only differ in ram size, wich is 512kbit max.
actually, it would be wiser to make a super fx pass-through adapter cartridge for tototeks super flash cart.
sa1 and sdd1 are a different story cause they use 16bit roms.
a genesis flashcart could be used for these, but youd have to write a new bootrom for it that runs on the snes and initializes the cpld.
making a super fx/sa1 all-in-one flashcart isnt feasible, youd basically end up with two flashcarts in one housing.
because the snes operates at such low speeds, cable length isnt an issue at all.
as long as everything is isolated properly, it'll be fine |
HyperLamer
Posts: 5559/8210 |
You could do that, but you would need to have every single chip inside the cartridge all connected to switches. That'd be one big cartridge, and the length of some of the wires connecting them would probably cause misreads. |
BGNG
Posts: 125/276 |
An easier form would be to have a switch installed on the cardtridge for whichever mapper you're using... for NES, at least.
SNES might not be so easy, since Super FX address space for Game #1 might be different than Super FX address space for Game #2. |
HyperLamer
Posts: 5553/8210 |
Hm, something I was pondering regarding universal NES/SNES flashcarts. Maybe a small CPU could emulate the various mappers and expansion chips? |
FloBo
Posts: 59/101 |
Anyway, if you want an all in one and easy to handle solution for most of the common games, go to http://www.tototek.com and buy their flashcart.
I have one and I don't want to miss it^^ |
BGNG
Posts: 122/276 |
Yup. ROMs can be transferred to in-system usable cartridges commonly referred to as "flash cards." These can either be imported from different regions, but they're considered "illegal contraband" in the United States. Look up Dr. V64 Jr. and Flash-2-Advance for some information on N64 and GBA cards.
SNES flash cards, on the other hand, have a few restrictions when it comes to this because there are so many different in-cart expansion modules that really make flashing a ROM difficult unless it doesn't use any. Things like Super FX and the such often compete with the same address space as each other across the library of games, so, to my knowledge, I don't think there's any "universal SNES flash card" out there.
Additionally, many make-shift flash cartridges have been created by system crackers on the scene; typically by creating their own circuitboard and mounting an EEPROM chip in it. |
d4s
Posts: 249/325 |
Originally posted by SoNotNormal
Can it?
sure.
have a look at my page, then: http://snesdev.romhack.de |
SoNotNormal
Posts: 21/793 |
Is it possible to transfer a ROM/Hack to a SNES cartridge and play it actually on your SNES? I heard a rumour about this and heard a lot of people saying it could be done. Just wanted to clairfy. Can it? |
hukka
