PET startup sequence?? (was LF: Commodore PET schematics, troubleshooting info)

Hi There are many kinds of test. The simplest effective test for stuck-at and address problems is the March C. It lacks many possible problems that are not simple stuck at. Worst case column test require various types of walks ( GALPAT is one of these ). Still, most simple RAM test Used by POSTs will do about as well as a March C. Now we get into some of the other problems of address line switching, retention and pattern problems. One need not include the entire memory in there GALPAT test. One can work in blocks and then work on a block to block sampling. It is a long test but then it does a lot of things that take a long time. I only suggested it because it seemed that he had an issue that a simple RAM test wasn't showing. I am involved with creating BIST engines for use on arrays in uP's I would never put a GALPAT in a production test but if I can get two address generators, it is easy to implement as a programmable element. It, along with other test, can often be used for diagnostic operations to help understand a fault until a simpler/quicker test can be used to detect that particular fault. Dwight