MK61 reverse engineering

This page is dedicated to reverse engineering of old russian programmable microcalculator MK61.

It is notable for it's unique architecture -- sequential bit processing, ring memory architecture, serial data bus.

The chipset is based on 145IK13 series microcontroller with different masks for different functions :

• 145IK1302 - master microcontroller: Display and keyboard drivers, memory partitioning, main functionality, synchronization
• 145IK1303 - slave microcontroller (slave 1): extended math functions: sin,cos ... etc
• 145IK1306 - slave microcontroller (slave 2): extended logic functions: OR, XOR ... etc