How long do the codes stay in the remotes without batteries?

pa911 · Post by **pa911** » Thu Nov 20, 2008 4:08 am

I was wondering how long I can have the remote programmed without batteries. If the learned devices and key moves are lost after a while.

By the way, how are the codes "programmed" into the remote - is it a real permanent storage or some kind of temporary way that needs power?

johnsfine · Post by **johnsfine** » Thu Nov 20, 2008 7:28 am

The remotes that can use some type of JP1 cable all have "permanent" storage for learned signals, key moves, etc. Batteries are not required to keep it programmed.

Some older OneForAll models, that are quite similar to JP1 models, have storage that only lasts a few minutes without batteries (and then only if you're careful not to press buttons while the batteries are out). But those are NOT jp1 compatible models. (For those, such as the URC7200 for which JP1 support could be added with significant difficulty, adding JP1 support includes adding permanent storage).

Post by **The Robman** » Thu Nov 20, 2008 7:44 am

For remotes with EEPROM chips, the programming is stored in the EEPROM so it will basically stay there for ever, even if the batteries are removed. This is true for flash remotes too.

For non-flash remotes that don't have EEPROMs, the programming is stored in the remote's RAM, so it will be lost when the RAM loses power. These remotes have a capacitor that is able to power the RAM for about 30 minutes after the batteries are removed.

pa911 · Post by **pa911** » Thu Nov 20, 2008 12:08 pm

...so do I understand correctly then, that the URCs with eg JP1.2 have an EEPROM and programming the remote actually programs the EEPROM?

WOW that is really cool - I remember very long time ago how difficult it was to program EEPROMs - one needed to use IR to burn it permanently as far as I remember...

nuke12 · Post by **nuke12** » Thu Nov 20, 2008 12:33 pm

pa911 wrote:...so do I understand correctly then, that the URCs with eg JP1.2 have an EEPROM and programming the remote actually programs the EEPROM?

WOW that is really cool - I remember very long time ago how difficult it was to program EEPROMs - one needed to use IR to burn it permanently as far as I remember...

Your thinking of EPROMs. IR to erase them but electrically programmable.

These are EEPROMs. Electrically programmable and electrically erasable.

Your JP1.2, I'm pretty sure it uses flash memory. Works somewhat like EEPROM memory but works on memory blocks vs byte access in EEPROMs.

Kevin Timmerman · Post by **Kevin Timmerman** » Thu Nov 20, 2008 2:38 pm

EPROMs are erased by short wavelength ultraviolet (UV). They can also be erased by X-Ray, but that is not practical for several technical reasons.

nuke12 · Post by **nuke12** » Fri Nov 21, 2008 12:34 am

Kevin Timmerman wrote:EPROMs are erased by short wavelength ultraviolet (UV). They can also be erased by X-Ray, but that is not practical for several technical reasons.

Ahhh ya, your right. I have an eraser unit too. I must be hanging around here too much and have IR on the brain.