daver2's latest activity

Don't forget that there may be some ROM code in the special function devices? Dave

Use one probe of the oscilloscope, with the trigger set for that probe and adjust the timebase from slow to fast until something...

There is no point unless we know that the address bus is working. How do we know what device is writing to the data bus (if anything...

According to this manual (which I can read better)...

You might want to start here: https://forum.vcfed.org/index.php?threads/looking-for-rqdx3-programming-examples.1210509/post-1210798...

Very probably. You should be able to dump the code - it should appear at 173000 (in a 16-bit system with a following wind). I should...

If the address buffers (U19 and U18) are enabled, the CPU address bus should appear on A0 to A12 of the ROM/EPROM devices. If we see...

>>> I had heard over the years that the SuperPet was designed to work along mainframes and minis but I never knew if that was true...

Let's explain a little bit more... The CPU (if it has a signal on pin 3 - SYNC) is fetching and executing instructions. We don't know...

+1 I am grateful for this as well - and have contributed myself (in a small way) to the future preservation of 'unobtanium'...

Someone is *always* going to be interested -- even if not now, definitely later. I am very grateful for those who have put up manuals...

Ah. It is now executing 'something'... Has this changed the LED light show on start-up? Dave

We don't want the timebase to be full scale. That is the FAST end. We want to SLOW it down. I am not sure what I am actually looking at...

Unless you have an MRV11-C (or similar) board to store some bootstrap firmware - yes, you are going to have to enter it via ODT...

Let's assume first that the problem is the person taking the measurements shall we? Dave