Is there a PCN or discontinuation notice for this part formally NATIONAL SEMICONDUCTOR CORP. P/N LM193H/883C

The LM193H/883 still exists; see the LM193QML.

Apparently, the C suffix was dropped before National Semiconductor was acquired by Texas Instruments.

Hello Thomas,

The Military devices (-MIL, -QML, /883, etc.) are not under PCN. They will continue to use the same die.

Only the high volume commercial LM2/393/2903 devices are under PCN.