SpritesMind.Net

Ok, I pretty sure it's a dumb question but I had to ask it, sorry

Looking at the price (and availability) of 5V DIP flash memory, is it possible to use TSOP/VSOP/PLCC/.... 5V Flash memory + adapter on a custom genny cart instead ?
I assume that if it's 5V, parallel and <90ns, it's ok....no ?
Like in SSF2....and perhaps Splatter House 3

I told you it was a dumb question !

yes you can use TSOp it's works fine with my custom cart.
5V 16 bit.

good luck

16bit is even hard to find so I think i'll go for 2x8

Oops, just when I complain about hard to find DIP 5V flash, I finally find something interesting....

huH?
this memory has only 32 pin , sega genesis Maskrom is 40 or 42pin

Those are 8-bit flash chips. You will need two of them, giving you a total of 1 MByte (8 Mbit) of memory.

What is the difference DIP or TSOP memory? There are more important parameters: volume, data bus width and access time. Is not it?

8bitwizard wrote:Those are 8-bit flash chips. You will need two of them, giving you a total of 1 MByte (8 Mbit) of memory.

Of course! I plan to follow something like Devster's dual rom cart

HardWareMan wrote: What is the difference DIP or TSOP memory? There are more important parameters: volume, data bus width and access time. Is not it?

I already aware of
acces time : < 90ns (70ns)
bus width : x8(byte) or x16(word)
but what do you call "volume" ?

KanedaFr wrote:

HardWareMan wrote: What is the difference DIP or TSOP memory? There are more important parameters: volume, data bus width and access time. Is not it?

I already aware of
acces time : < 90ns (70ns)
bus width : x8(byte) or x16(word)
but what do you call "volume" ?

Capacity. Size. In russian, volume and capacity are very close things when you talk about memory.

Last (?) question on this subject....

a lot of the newest chips are 3.3/3.0v
I know I said I was looking for 5V chip but I found some 64M 3.0V x16 bit Flash rom...
Unfortunatly, a 3.0V chip will use 3V on IO pin while a 5V chip will use 5V on IO pin....and I doubt the genny will like the 3V output on data pin nor the 3V chip will like the 5V input on adresses pin, even using a 5v->3V on rom VCC pin....or did I miss something ?
Did I need something like a bus switch like on this ParaFlasher ?

Some 3V ICs are 5V-tolerant. There are level convertors as well. In one of Flash carts (for SMD) schematics I recall was used 3V Flash with a lot of resistors to convert the levels. Here is the schematics of the cartridge (bottom part of page 3).

Normal TTL data level is like 0.2V low and 2.8V high, which is why 3.3V became a standard. There shouldn't be a problem as long as you can get a voltage converter for the 3.3V power.

It's what I read on .... this same forum (thanks Google!)
So what the use of a bus switch ? I found another source talking of this...

Wow!
Spansion(AMD) now got 2Gigabit parallel rom !
3V and MirrorBit NOR (?!)

I used a bunch of 220ohm resistors on the signal lines in one of my flashcarts that uses a 3.3V flash chip.