There are at least 2 versions of this ECU: One with and one without knock sensor. The ECUs with a knock board have R118,R119 and R101 while the knockless boards have nothing there. Instead, R118 and R119 are moved to R142, 143

See Remove AKnock Sensor for some details about the knock difference.

Some Knock board even use an external ROM! The only difference is that it seems to be missing R15 if you compare it to the regular Romless boards

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%META:TOPICINFO{author="Artifex" date="1086145440" format="1.0" version="1.1"}% P14

93-95 OBD1 Prelude Si (non Vtec - H23A)

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