Does anybody know if Winbond chips are OK?

[Charlescrown]

Just looking around at chips. I am currently using SST 27SF512 and they work great but looked at the Winbond W27C512. All the pins are the same but the speed is slower. Question is are they suitable?

[delcowizzid]

as long as they are 120ns or faster shouldnt have a problem

[vlad01]

I'd say so if antus linked me to some just the other day. All sold out since then thats was only the other day too.

I found these on ebay where the price is high and not shipping from china, speed is 45ns too.

Not sure if they are legit though. pretty damn expensive so you'd hope its genuine.

http://www.ebay.com.au/itm/1-x-PH996510 ... 232a5f0b4c

[Charlescrown]

Man for 1 your kidding

[Charlescrown]

Delcowizzard whats the problem if their slower?

[vlad01]

whats the minimum size the EEPROM can be? I can't seem to find 512k ones anywhere but 256 seems to be more common.

[vlad01]

Delcowizzard whats the problem if their slower?

CPU can't access the data fast enough. So I guess it would cause the ECU to hang/crash maybe?

[Charlescrown]

Yea 256 should be OK with 12P. I think using no offset when burning the program as I now use offset of 8000 to halve the chip.

[vlad01]

problem is reputable electronic suppliers like farrnel and mouser don't offer anything faster than 150ns

and the 120 and some 85ns ones they state as NLA and no longer manufactured. Price is ridiculous too. 20 a pop is the cheapest I can find anywhere for not even suitable chip.

I wonder if 32 DIP can be used instead? Looking at the pinout it 2 extra address lines otherwise it looks the same.

[vlad01]

lol I just found a 70ns 512K prom.... on an old nvidia TNT2 card. pulled the sticker off the chip to find a posibly useable EEPROM.

looking for the data sheet I found this russian site. looks like old graphics cards are a good source of EEPROMs

http://old-pc-museum.narod.ru/index/0-30

off the site.



EDIT, looks like OTP damn!