nesdev.org

Okay, thanks!

I'd always been curious about that little extra bit where the mask ROMs were soldered in, the markings clearly indicate that it's for a larger mask ROM, but I've never seen on that big being used.

Yes, the wiring is different depending on the chip used. A lot of the chips use standard pinouts, but even then, the "standard" pinout can be different depending on the capacity of the chip (in the case where you have 2 different capacities with the same pin count). Check the datasheets a...

Thanks for the info! You also won't be able to use an x16 ROM (so be careful there, I've made that mistake. For instance the vast majority of Microchip's parallel Flash ROM lineup is x16). x16? Like, 16 bit or something? That's not a term I'm familiar with (unsurprising, since I've only just recentl...

Is THIS the chip you're talking about? I notice it's an eeprom, while the 8 megabit chip I was looking to use is an eprom, it's safe to mix eeproms and eproms right? The SST39SF040 isn't an EEPROM, it's a Flash ROM (which, I suppose is technically an EEPROM, but you don't typically call Flash ROMs ...

It works out to be about $6 for both chips, vs $12 for the 29F032 and TSOP adaptor :D With regards to brands, obviously AMD is a good choice for the 27C040. For the 27C801, I've got a choice between ST, ATMEL, MXIC and NEC. NEC is the only brand I recognise there, so them maybe? They're all DIP32 w...

It still boggles me that putting a second copy of half the ROM, into the ROM and doubling that (ending up with 4 copies of the back half the ROM and 2 of the front in the one ROM) doesn't break the ROM horribly. It's called "incomplete decoding". As long as a given set of signals on the a...

It works out to be about $6 for both chips, vs $12 for the 29F032 and TSOP adaptor :D With regards to brands, obviously AMD is a good choice for the 27C040. For the 27C801, I've got a choice between ST, ATMEL, MXIC and NEC. NEC is the only brand I recognise there, so them maybe? They're all DIP32 wi...

Whoops, I'd forgotten tepples had said that :P Hmmmm, in that case, and following on the idea of using two eproms like the original cart, what about if I used 1x 8 megabit eprom (say, a 27C801) and 1x 4 megabit eprom (say, a 27C040)? That adds up nicely to 12 mega bits, which means no mirroring and ...

Hmmm, it seems like I've got quite a few options when it comes to padding out the size of my ROMs. I can use a hex editor to duplicate some of the data, I can split the file (does SNES ROM UTILITY achieve the same splitting results as SNES TOOL?), pad out the smaller one, re-join them then double th...

"larger chip and smaller chip"? Don't forget, I'm using a single 32 megabit eeprom here ;) Or are you describing this process? If you want to pad your rom with zero's. You can use ucon64 to do it and then split it into two 8mbit files. ucon64 -p rom.smc (do this 4 times) ucon64 -s rom.smc ...

Back in the day I used to use DOS... I'll give it a shot... *EDIT* CHANGE DIRECTORY TO F:\ YOU BASTARD!! WHY WON'T YOU OBEY? *EDIT* AH HA! GOTCHA! Okay, I've got the ROM to 24 megabits. Putting a second copy inside the ROM seriously doesn't break it? Madness! *EDIT* There's apparently a program call...

I know nothing about hex editing :P Can you give me a quick run-down on how to do what you've just described? Google's not coming up with the goods. I mean, I've got the ROM opened up in Hex Workshop, but I have no idea what I should be copying. I mean, where's the notches that indicate where each m...

If I'm using a 29F032 eeprom (a 32 megabit chip) and I put a ROM that's smaller than that on there, do I need to worry that there's free space on the eeprom? As long as you tie the unused address lines to ground. For example, with an 8 megabit game on a 32 megabit chip, you'd ground the two most si...

Good to know! Thanks! Okay, I think I know almost everything I need to know about SNES repos! Thanks for all your help guys! A few final questions: 1) If I'm using a 29F032 eeprom (a 32 megabit chip) and I put a ROM that's smaller than that on there, do I need to worry that there's free space on the...

As I understand it, LoROM and HiROM have nothing to do with speed. There are SlowROM and FastROM, and FastROM games need 120 ns or faster memory, but (correct me if I'm wrong) FastROM games can be either LoROM or HiROM. LoROM vs. HiROM: Function of A15 vs. A22 SlowROM vs. FastROM: Whether or not 13...