Recent content by Radix

Ah - well that is about as minimal as you can get... I'm not sure if you have had it booting OK? - It would be good to see it boot from the known good SCSI card, for instance, just to prove the where the issues are - sorry if you have already done this! Robin

Hi Jack, Ah well there will be some DEC kit on display there later in the year... should be lots on FB about it in a couple of months.. Thanks for the offer - we have a working one in a museum system I can scope around for comparison if need be, but not out of ideas yet... I like the idea of...

Hi - Thanks for the reply, I'm Robin It seemed like there was still likely to be a seal on one side or the other, and actually any leak would be of pressurised filtered air when the disk was spinning, so I left it alone... The coarse filter material was a very coarse open material, that we...

Hi - I have been repairing a couple of Gigis and had this problem - I have a small Sony professional monitor that works well - and some of the larger ones are also suitable, but the frequency is not quite standard PAL... Mine is a PVM-9045QM You also have the mono output that can usually be...

Hi - it sounded like a bus grant / board position problem - can you show the actual board layout? - Or put the scsi controller in your chassis and see if you can boot that?

Hi - On my ESP32 projects with SD cards, I found it best to use cards between 4GB and 16GB - both larger and smaller ones had problems, there are many variations in the feature set - also , I would try a single FAT32 partition unless you see reason not to. I take it you have found working 10MB...

Looks like some sign of water damage on the wires on the caps in one photo - maybe some connection with them failing, the supply is current limited, but they can certainly get very hot if they draw even 0.2A and don't trip the current limiting... Don't over think it, replace them if they fail...

Most of the time, it's the timing cap - although I have had one where the 1M resistor went open... It got a 470K put in instead - somewhere there's a PET that boots REALLY quickly... If the board is really gunky - there can be enough leakage to stop it working as well...

Ooh good luck with the RLV12 emulator - my real RLV12 is faulty and not got round to trying to fix it yet.. I get lost on that guys site - he says the emulator is available but I can't see where from, lol... Does it expect a particular file structure or format on the SD-Card?

That's not sounding too bad, I'm surprised the CPU is not running warmer! - if you still have the original DEC connectors with the square pins, it's common to get a blackened or pitted row of marks on the pins where the one side of the connector mates, which can get hot - they used the same...

Bear in mind that DEC had overheating issues with a 36A supply split between all the connectors... Also - voltage drop to the backplane is critical - the DEC PSU is specced at 5.1V out... FYI, I have spent a lot of time repairing DEC backplane and PSU connector solder connections that have...

It works well to make the ODT state machine the top-most level function (after whatever initialisation stuff you need!) - then you can call the actual emulator if in "RUN" and return to ODT when it exits, again calling the emulator on "P" or "G" instructions, and returning to ODT on halt...

Hi - FYI, forced air cooling across the boards ad backplane is NOT optional. DEC had 2 fans of at least 100cfm cooling the boards and PSU - you will drastically shorten the life expectancy of any board used without cooling in this manner. Please sort the cooling arrangements and save the...

If you go to display setup and selet colour or colour+mono, you should get this:

It could be DU0, 1, 2, or 3 as well - you will know when you have one of the the two correct numbers as you will hear the drive when you try and access it... the lower number should be the top / left drive