Revive 11/34

AFAICR (?), the M7859 is sort of a UNIBUS device. The (front panel) console only communicates with the M7859. The M7859 writes/read to/from memory using the UNIBUS. Have a look at the schematics of the console. I cannot remember whether a demux for the displays is on the console PCB, or on the M7859. I also have a few dead M7859?s too. Of one I know that one of the two 4-bit memory chips is faulty, the others I never investigated. If you get 000000 on the dsipaly and when halted it shows 173066 I presume it is looping. You can use the front panel to single step. If it loops, it will repeatedly read from a device address which is most likely the CSR of the boot device. 173066 is an address of the boot PROMs on the M9312. So, your 11/04 seems fine so far ? ________________________________ Van: cctalk <cctalk-bounces at classiccmp.org> namens Noel Chiappa via cctalk <cctalk at classiccmp.org> Verzonden: Saturday, December 9, 2017 5:15:18 PM Aan: cctalk at classiccmp.org CC: jnc at mercury.lcs.mit.edu Onderwerp: Re: Revive 11/34 Yeah; you can use the G7273 as a 'crib', since it has the NPG jumper on it. That jumper goes from CA1 to CB1: component side, third connector (counting connector end). A lot of the slots will still have their jumpers in, which is how you can confirm you're looking at the right pins; look for slots without them. Yeah, the M7263 is the KD11-D CPU, the M7847's are MS11-E's (one of them will be useful as a first-stage debug for the 11/34, once you've verified, in the -11/04, that they work - the M7891 MS11-L is rare and valuable, I'd rather not use that until everything up to that point in the -11/34 is known working - you could try pulling the two M7847's from the -11/04 and try plugging in the M7891, to verify that it's sort of OK). As always, first pull all the boards and check the power supply (if it's been a long time since it was last powered on, re-form the electrolytics in the power supply first, before powering it on), then put in the _minimal_ set of boards and get those working. Yup, that's working. Now you have a working machine, you can board-swap in The first thing I'd try would be the M7859, KY11-LB, from the -11/34 over here. If it doesn't work in the -11/04 (with only that board changed), i) you've isolated the problem, and ii) you can probably use the one from the -11/04 to get the -11/34 working (unless there's something _else_ broken in the -11/34 as well). NOTE: Don't plug the good one from the -11/04 into the -11/34 - or do anything else with the -11/34 - until you've checked the voltages in the -11/34!!! If the M7859, KY11-LB from the -11/34 _does_ work in the -11/04, time to keep looking. The console itself is so dumb it's unlikely to be the problem, but you never know; might we worth swapping. I'm having a hard time seeing what problems in the /34 CPU, etc could cause the symptoms you're seeing - are they still there with only the absolute minimal board set? Noel