![]() ![]() Later things have changed and it became better to use simpler ICs like RISC processors (Reduced Instruction set) which means less instructions but faster processors. This unfortunately made CPU's very complicated. Back then it was "very good" to have CPU's with many and versatile instruction sets. This IC is one of the very first generation of CPU's. Read-out is going directly towards the output pins, so we test this memory in the output section of the test. So the test program can write but not read IC23. One last remark, the memory chip IC23 is not included in the memory test, this is impossible, as the data is being written through the databus, but reading does not happen through here. It was necessary to test the inputs, as this board does not use PIAs for in- and output, and several chips are involved in the input. The same if we switch "on" the DIP switches on the cpu board. Here we shall connect the input pins at connectorsCN11 ( there are 8) and CN8 (there are 4) one by one to ground, and every time the cpu led should light. If both memory chips are ok, the test will automatically continue the "input test". If something is wrong then the test will continue to run the memory test. ![]() At startup all outputs will go up and down in rhythm, between 5 and 0 volt. The test program consists of three parts. David did try out the repair method and apported positive remarks and corrected a lot of sentences.You should visit his site, as a lot of technical information about Zaccaria is collected, and it was the only website on which I found some technical information. who has provided me with several datasheets, also his website and documents about Zaccaria were a good approach to these Italian pinballs. I'd like to start thanking D.Gersic from the U.S.A. Second generation Farfalla, Time Machine, Magic Castle, Soccer King, Pinball Champ, Devil Riders ![]()
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