Hot rodding a 27C128 dinosaur

krusty · Post by **krusty** » Sat May 07, 2011 9:53 pm

I am trying to put together a smarter type of RT and need to swap the EPROM to an EEPROM with 512k or better to allow $12P to operate.

What's the way to go?

Post by **antus** » Sun May 08, 2011 12:47 am

You need nvram for RT (real time). 256kbit is 32kb which is enough for $12p. the 27cXXX chips (eprom) are pin compatible with 29cXXX (eeprom) so you can just swap one right in. You'll need to pull it out and either use an adaptor on the whole memcal, or put the chip in a socket so you can pull the chip out the memcal, then you'll be able to erase and write without bothering with the uv erase cycle. Its a step up, but it wont give you realtime.

krusty · Post by **krusty** » Sun May 08, 2011 12:55 am

antus wrote:You need nvram for RT (real time). 256kbit is 32kb which is enough for $12p. the 27cXXX chips (eprom) are pin compatible with 29cXXX (eeprom) so you can just swap one right in. You'll need to pull it out and either use an adaptor on the whole memcal, or put the chip in a socket so you can pull the chip out the memcal, then you'll be able to erase and write without bothering with the uv erase cycle. Its a step up, but it wont give you realtime.

I already have RT but it's not my car so I want to have a dedicated tuning memcal with the capacity to run $12P and also make a 512k standard but EEPROM memcal to run in the car between tuning sessions which will only be fortnightly

vn5000 · Post by **vn5000** » Sun May 08, 2011 10:26 am

Use a 27sf512 ,its a direct drop in.

krusty · Post by **krusty** » Tue Jun 21, 2011 12:46 am

I have a 27C256B soldered in place of the old 128 pos. Still can't get my head around offsets dammit.

I know I need to write the 32k bin to the end of the eprom but am not sure where to start it.

Tried multi filling it from 0-7fff, 8000-10000, 10000-18000 etc but no luck.

What am I doing wrong?

Post by **delcowizzid** » Tue Jun 21, 2011 1:08 am

a 27c256 will take only one 12p bin just program from 0000 onwards LOL

krusty · Post by **krusty** » Tue Jun 21, 2011 5:58 am

I tried that and it didn't work

Post by **delcowizzid** » Tue Jun 21, 2011 6:10 am

by didnt work you mean the car wont run on it or it wont program

krusty · Post by **krusty** » Tue Jun 21, 2011 8:51 am

delcowizzid wrote:by didnt work you mean the car wont run on it or it wont program

Won't program. That's why I was clutching at straws lol

It's a brand new EEPROM too.

Post by **delcowizzid** » Tue Jun 21, 2011 9:09 am

did you erase it for 5-6 minutes in the uv eraiser

Hot rodding a 27C128 dinosaur

Hot rodding a 27C128 dinosaur

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