Using non DIP memory

Post by **KanedaFr** » Wed Jul 28, 2010 9:49 am

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 !

bastien · Post by **bastien** » Wed Jul 28, 2010 10:36 am

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

good luck

Post by **KanedaFr** » Wed Jul 28, 2010 11:09 am

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

Post by **KanedaFr** » Wed Jul 28, 2010 3:31 pm

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

bastien · Post by **bastien** » Wed Jul 28, 2010 5:55 pm

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

8bitwizard · Post by **8bitwizard** » Wed Jul 28, 2010 10:01 pm

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

HardWareMan · Post by **HardWareMan** » Thu Jul 29, 2010 7:37 am

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

Post by **KanedaFr** » Thu Jul 29, 2010 7:44 am

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" ?

HardWareMan · Post by **HardWareMan** » Thu Jul 29, 2010 9:03 am

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.

Post by **KanedaFr** » Thu Aug 05, 2010 12:36 pm

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 ?

Shiru · Post by **Shiru** » Thu Aug 05, 2010 12:47 pm

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).

8bitwizard · Post by **8bitwizard** » Thu Aug 05, 2010 1:24 pm

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.

Post by **KanedaFr** » Thu Aug 05, 2010 1:28 pm

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...

Post by **KanedaFr** » Thu Aug 05, 2010 1:32 pm

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

TmEE co.(TM) · Post by **TmEE co.(TM)** » Fri Aug 06, 2010 6:52 am

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