Description:

Overview

This chipset is found in the late model 55sx. It operates at 16MHz. Most of the IBM chips have an unclear function. The 23F9177 was replaced with the 37F0728 at some point. It is basically the same as the model 65sx chipset, however the 65sx lacks a 27F4620.

Documented parts

• IBM 23F8566
• IBM 23F9177
• IBM 27F4619
• IBM 27F4620
• IBM 57F1139
• IBM 90X8134 (DMA)
• Intel 8042AH (Keyboard Controller)