Texas Instruments Proprietary IC's?

[shrtrnd]

Trying to identify some 14-Pin DIP IC's, made by Texas Instruments.
Does anybody know anything about the markings, and what they might cross to?

158-2606
158-2763
158-5996
158-9129

I don't know if they're some obsolete family of IC's, or proprietary markings for some company. Anybody seen this type of marking before?
Thanks

 

[Resqueline]

It's typical proprietary/ in-house markings. HP had 4-4 digit markings for instance. These could be standard TTL circuits if they are a little aged. If you find no clues on the net your only option is to assume something and test them in some (safe, current limited) way.