general-purpose UART Companion Memory The 8061 was used with a family of other devices, including the 8361 – a companion memory having ROM and some RAM. In later modules, one-time-programmable (OTP) EPROM memory was substituted for the original mask-programmed memory – this greatly simplified logistics given the wide variety of ROM codes required in each model year. External links Technical Notes on The EEC-IV MCU (PDF) Technical Notes On The EEC-IV MCU updated Intel microcontrollers