Posted by dapj20 on Jun 08, 2020 in MCS48, Microcontroller-Circuits
The Early Microcontroller : 80C39 is a CMOS Version of 8048 the one that preceded 8031-8051. MCS48 is the set for that, MCS51 is the current set.
Process Controller code here 80C39 Code for MCS48
Digital to Analog Converter with uC Watchdog is the front end and an external hardware watchdog of an early kind. These are simple but robust circuits and worked well in noisy environments.