What could be considered as the correct size for the data found in the ROM of the Sega Saturn carts ?
As I am a novice in all the ROM stuff, I don't know which size to take.
Here is an example:
Let's take the Satellite cart.
It has 3 chips:
1) PALCE16V8H-10 - P8/4 9450AXA/L - AST94237620-001A - 20 pins=> probably CMOS
2) 27C256-20 - 8831 HKB - PGM@12.5V - 28 pins => probably 256K (32K x 8) CMOS EPROM
3) M27256-25F1 - ST9022 - 6212424 - A40360 - 188 116 - 28 pins => probably NMOS 256K 32K x 8 UV EPROM
The data is contained by the chip 2) and/or 3) (as I said, I am a novice), both are 256K chips.
Ok.
On the other side, by checking the memory of the saturn when the satellite is inserted, you can see that the data of the satellite is 64K long, mirrored 8 times (total = 512K).
So, what could be considered as the correct size for a ROM dump of this cart ? 64K ? 256K * 2 ? 512K ? Any other size ?
It seems most of the Saturn carts have mirrored data. I only found 2 or 3 ones that don't have mirrored data, out of more than 80 carts tested. (it seems to bethe same for MPEG Carts).
As I am a novice in all the ROM stuff, I don't know which size to take.
Here is an example:
Let's take the Satellite cart.
It has 3 chips:
1) PALCE16V8H-10 - P8/4 9450AXA/L - AST94237620-001A - 20 pins=> probably CMOS
2) 27C256-20 - 8831 HKB - PGM@12.5V - 28 pins => probably 256K (32K x 8) CMOS EPROM
3) M27256-25F1 - ST9022 - 6212424 - A40360 - 188 116 - 28 pins => probably NMOS 256K 32K x 8 UV EPROM
The data is contained by the chip 2) and/or 3) (as I said, I am a novice), both are 256K chips.
Ok.
On the other side, by checking the memory of the saturn when the satellite is inserted, you can see that the data of the satellite is 64K long, mirrored 8 times (total = 512K).
So, what could be considered as the correct size for a ROM dump of this cart ? 64K ? 256K * 2 ? 512K ? Any other size ?
It seems most of the Saturn carts have mirrored data. I only found 2 or 3 ones that don't have mirrored data, out of more than 80 carts tested. (it seems to bethe same for MPEG Carts).