ECU Guru's (writing to an EPROM)

[DjLiquid]

I recently bought my Willem EPROM programmer off eBay and installed the software it came with. It's a pretty standard program that will allow you to erase whats on your chip and then write to it. I have it all setup and have the new bin files to which I want to write to it but Im having a few probs.

The chip is being read by the programmer. I can see the bin file on it. I can erase whats on the chip (supposedly since thats what it says and u can see the progress bar doing it), but I cant write to it. I get an error that says "Error at 0x000035 Chip=0xB2 buffer=0xB0"

Now, thinking logically breaking down EPROM into two words, EP (meaning the type) and ROM (Read Only Memory) states that I should only be able to read but not write to the chip.

Am I going to need to buy another chip? Or is it the way I am programming the chip? Do I just need to change the settings?

[mbmbmb23]

EPROMS need to be erased with UV light....most likely with an EPROM eraser. EEPROM are the newer technology and can be erased electronically....but you most likely will pay more for them and not find 128k chips.

-m

[mikesim]

EPROM - Erasable Programmable Read Only MemoryEEPROM - Electronically Erasable Programmable ROM

there's some info on writing to a ROM that's bigger than the normal block size. i can't recall it offhand, but say if the bin were 128K and your chip was 256K, you need to write to it twice to work, but i don't know if that would actually have anything to do with the burning of the chip.

also, have you gone to the ecu forums?http://ecu2.forumwise.com/view...489f9
Modified by mikesim at 12:32 AM 5/14/2007

[DjLiquid]

After thinking about this:

Erasure of an EPROM chip is accomplished by exposing the chip die to ultraviolet light. Most EPROMs are manufactured with a quartz window over the die to facilitate exposure (some have no windows, and therefor can be programmed only once.) Once the chip is programmed, an opaque sticker that doubles as a data revision label is affixed over the top of this window to preserve the contents.

Im thinking it may be possible for me to do it this way.... I go tanning =). What if I were to take it into a tanning bed with me for 20 minutes? The wavelength may not me strong enough but over prolonged exposure, it should erase the chip. Right?

[c-rad]

Or you could just buy an eeprom for $3 or $4 and use it over and over and save yourself the hassle. I heard leaving it out in the sun for a few hours works too.

[tineira]

you could try that, but be sure to do a blank check before programing. But the best idea is to follow what c-rad said.

[progman]

Someone correct me if I'm wrong but EEPROMs don't work with the factory ECU.

Thats what I've heard.

Also leaving the chip out in the sun.. good luck on that. I heard it should takes days and it may not be completely erased.

Question for anyone who writes ROMs:

using a 256K chip do you actually write the ROM twice to the chip in the begening and end of the chip or do you add the files to together then write one file?

cat rom1 > rom256cat rom2 >> rom256

Thanks.

[c-rad]

Someone correct me if I'm wrong but EEPROMs don't work with the factory ECU.

Thats what I've heard.

Also leaving the chip out in the sun.. good luck on that. I heard it should takes days and it may not be completely erased.

Question for anyone who writes ROMs:

using a 256K chip do you actually write the ROM twice to the chip in the begening and end of the chip or do you add the files to together then write one file?

cat rom1 > rom256cat rom2 >> rom256

Thanks.

Eeproms work perfectly fine.Yes, leaving it in the sun works. As for how long, who knows? Either way its not the proper method to erase them.And to burn a 128k file to a 256k chip, you fill the buffer once from 0000-3FFF and then again from 4000-7FFF.