I've only had a brief look around this ECU, it uses an Hitachi HD63B03 processor combined with an HD63140 Universal Pulse Processor
(UPP). The UPP is a quite powerful timing processor that gives this ECU a lot of capability considering its architecture. The external EPROM
is a 27C128, I have read the binary and carried out a basic disassembly. The F5 ECU has no lambda sensor so there is no closed loop capability,
unlike the I2 ECU it only has one timing map.