whats an eprom???

[maverick27]

hey guys imma sounds like a total idiot but whats is an eprom??? i looked it up and joewagon game me a great link but i still dont get it. help me please.

this is whats said about it on vfaq.com:

What is an EPROM?
What is an EPROM ECU?
An EPROM is an electrically programmable read-only memory, or a type of computer memory that can be programmed only once, but read an unlimited number of times. EPROM ECUs have such a memory IC installed in them. This memory holds the program code that controls the ECU behavior. The EPROM is a separate chip from the microcontroller (computer chip) that actually runs the program. This makes it easy to change the ECU programming, since only the EPROM need be replaced, and EPROMs and their associated programming tools are relatively common.

The alternative, a non-EPROM ECU, does not have an EPROM. Instead, the program is stored inside the microcontroller itself (technically, in embedded EPROM memory that is part of the microcontroller). This makes it hard to change the ECU programming, because the microcontroller needs to be replaced. These are difficult to get, and require special programming tools that are equally difficult to find.

[jdoug]

Basically all you need to know as an Eclipse owner is that you need an EPROM ECU in order for DSMLink to be installed onto it. The EPROM chip allows the ECU to be reprogrammed with the DSMLink code. Only 1995 ECUs came with EPROMs (in 2Gs anyway), so you will need to find a 1995 ECU if you're gonna get DSMLink. I highly recommend DSMLink, BTW.

[kjewer1]

An eprom is just a type of chip that can be reprogrammed on the fly. When you make changes in DSMlink, or when they make your keydiver or TMO chip, the programming is changed to reflect what you are trying to do. You cant make any changes to ECU code for tuning purposes without it. So like jdoug said above, you need it to be able to change the ECU code with DSMlink.

The other peculiar thing about eprom ECUs is all of the code is on that particular chip, as mentioned in what you cut/pasted above. Without access to this code, you cant change it. So when you have this chip, it can be changed out for a TMO or keydiver or similar chip with different code on it. It really is that simple. Non-eprom ECUs wont have this seperate chip that we can easily change out (tmo or keydiver) or reflash on the fly while tuning (dsmlink).