Description:

Overview

Found on the model 70 Type 1 motherboard. It supports 16 or 20MHz operation. It is similar to the Model 80 T1-T2 chipset. It differs in that the 80 uses the 72X7377 DMA and this uses the 90X8134 DMA. This chipset appears to use discrete logic and two Intel 8259-2 (Programmable Interrupt Controllers), in order to interface the the 386 CPU. This logic has not been investigated further.

Documented parts

• (any brand) Discrete Logic
• IBM 15F7917
• IBM 72X8299 (I/O controller)
• IBM 90X8134 (DMA)
• Intel 8042AH (Keyboard Controller)
• VLSI VL82C114 (Combination I/O)