ESS ES1989S Allegro motherboard sound controller.

Looks like 350 nm 3-metal or so and appears to be the same process as the Silicon Image SII164 although so far it's not known which fab this is.

The number for a 1977 patent on speech synthesis is marked on the top of the package.

Package

Markings:

  (ESS logo)
  Allegro (TM)
  ES1989S L510
  TSU28883S
  (P)4,214,125 (C)

Die

Size is approximately 5360 x 4040 μm (21.65 mm²)

Overview

Logo/markings. Looks like 3 metal layers since there's 3 via masks.

Random logic