There are always two EPROMs that contain the standard "baseline" software for the OCSS. These are locations Z37 and Z52.

There MAY be two additional "contract software" chips, which are also EPROMs with job-specific software for adding customer-required features to the OCSS. These are locations Z36 and Z53.

The EPROMs will have an opaque UV-proof sticker on them that should have the software version printed on them. If not, you should be able to use the Service Tool (black) or Otis Field Tool (blue) to access the software version information. With that information, you should be able to get a copy from Unitech (assuming they will sell it to you). Or, you should be able to copy the chips from another E411 car's OCSS assuming it has the same version. Often, maintenance companies will take a snapshot of the chips contents as a backup, so check with your company office.

Normally if the EPROMs are corrupted, the OCSS won't run, or you will experience random resets of the RCB II when it tries to execute the corrupted software routines.

In addition, you will always have two contract data EEPROMs. These are locations Z34 and Z49. The data in this sets the configuration of the OCSS. If you don't have a backup, you can start with a copy from another job and try to reconfigure the data to match the affected elevator's configuration. There are a LOT of parameters and this is not for the faint-hearted. The I/Os will be shown on the diagrams, so you can definitely see what ones are used and figure out what address and pin they are using, but you'll still need the OCSS documentation to know what I/O numbers each of them are in order to set them up.

If your EEPROMs go bad, which can happen because of excessive writes, you should be able to copy them to a fresh set of chips. It's possible that whatever data location(s) can't be written may have slightly weird data in them, depending on what exactly went wrong when they were last written to.

Good luck!