mic_ wrote:My Neo2-SD (non-Pro) has one chip from ST. I can't quite make out the part number, but it could be M36DR432A (which would be a 32 Mbit flash + 4 Mbit SRAM chip).
Then there are two chips labeled 4050L0YTQ2, which according to google are flash memories made for mobile phones (by Intel?). Dunno what their sizes are.
The Neo2 Pros aren't translucent so I have no idea what they contain.
Thanks, I have a translucent Pro, so I can check what's on it.
I looked again at the old PC client software I have, and the SlimLoader IV looks pretty simple: you do bulk transfers to cart to do read/write operations. The first byte is a command, and is followed by a variable amount of argument bytes.
Command:
b3 = 0=discard read data, 1=return read data
b2 = clear internal return buffer? Not sure about this bit.
b1 = 0=GAME ROM BUS, 1=SAVE RAM BUS
b0 = 0=READ, 1=WRITE to GBA cart
READ GAME BUS outputs the next three bytes onto the game rom bus, and does a read operation. You set b3 of the command to return the read data in a bulk USB transfer in after the command bulk transfer out is done. If you don't set b3, the data read from the cart is ignored. I'm not completely sure what b2 does, but it's normally set for the first read that returns data, and clear for all other reads, so I'm guessing it clears the buffer used for holding the data read until the bulk input transfer. You get two bytes for each read operation since the GAME BUS is a word bus.
WRITE GAME BUS outputs the next three bytes on the game rom bus, and the next two bytes after than on the data bus. Again, b2 is normally set for the first write, and clear for all remaining writes.
READ SRAM BUS outputs the next two bytes on the save ram bus. The save ram bus is only 16 bits, and reads/writes a byte, so if you set b3, a single byte is returned for each read operation.
WRITE SRAM BUS outputs the next two bytes on the save ram bus, and the next byte on the data bus.
And that appears to be all there is. Those four operations allow you to do everything on the GBA cart. In fact, doing the proper operations on the game bus would allow you to read SD cards through the SLIV just like on the console. It wouldn't be remotely as fast as using a dedicated card reader, but it would work.
Note that this is all geared towards the GBA cart... I'm not sure how it would handle the extra stuff in the N64 cart - you can also read/write the U2 menu flash in the N64 cart via the usb, but it's not part of the GBA bus. My guess is the U2 menu flash sits on the GBA bus behind the N64 Myth CPLD and looks for some kind of setting that is not normally used on the GBA cart that it then decodes for the U2 flash.
