Where can i find a fw for 1635sx that can be used with

omnipatcher?

the external one

5s drives aren’t supported by omnipatcher and probably never will.

ok what bout same for new 165ps one and so forth?

omnipatcher only supports drives up to the 1693S. newer drives may never be supported.

You can find unscrambled firmware for the LiteOn 1635S on this page:

http://codeguys.rpc1.org/firmwares.html

The 1635SX and 1635S firmwares are exactly the same (or at least the latest YS0W version is bit-identical for the two drives).

Omnipatcher doesn’t support modifying 5S or 6S firmware, but MediaCodeSpeedEdit does have support for these drives, and should in theory be able to perform strategy swaps and/or disable supported write speeds.

I haven’t actually tried flashing a firmware to my LiteOn 1635S that was modified by MCSE, so I have only theoretical knowledge of this support.