All in all, the configuration shows this unit is not supposed to do any advanced tasks. Seems to be a control board for something. Digital signals produced by that 40-pin micro controller are converted to analog ones by the rest of the circuit, and then are probably applied to the power section, that is, those big parts with heat-sinks, which instead of vacuum tubes are now solid-state (Transistors, hybrid power ICs versus vacuum tubes). To my untrained eyes, they've used a basic micro controller, couple of digital to analog convertors, some LM324 Op Amp ICs, and some 'glue' logic ICs. All of which are old and famous off-the-shelf parts. For example that LM324 dates back to mid 1970s, and that micro controller (an Intel MCS-51 family) and that DACs to early/mid 80s. The boards also seem to be double-layered. Not very modern, but it's what it has been intended to be, a cheap and reliable solution. I think a higher degree integration with more professional look is possible through using other micros also available in Iran and/or through using SMT/Multi-layered boards.