I would assume that your 11/10 has the suffix -NC.? There were two versions, the -NC used -15V four wire memory, and the later -SC used +20V three-wire memory. The +20V was provided by a MUD slot (Modified Unibus Device) and there was usually a big red sticker in it warning to not plug a module in that was not wired for it. I believe it was standard in all models after the second version of the 11/05 -/10 I once tried to fix an 11/34 off-contract that somebody had done exactly that to- I gave up when I found that the +20V had been routed to some unobtainable ROMs on the CPU board. cheers, Nigel Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, the origin of the open-source concept! Skype:? TILBURY2591nw.johnson at ieee.org On 2022-01-09 17:04, Chris Zach via cctalk wrote: > I'm working on my pdp11/10 getting it back together. One problem I > think I have is that the secondary memory (a Plessy 700101-100) may be > shorting the -15 line for some reason. Working on it, but does anyone > have a manual or anything like that for this kind of memory board? > > Alternately, what kind of Unibus 16k memory board exists to get a > 11/10 from 16kw to 32kw of memory? Apparently I can't use a MM11-B as > it requires +20 and -5, both of which are not provided by the power > supply or sourced on a DD11-B backplane module. The 11/10 has +15, > -15, and +5. > > On a related note, where did +20 come from for Unibus and which > systems even supported it? Was it an 11/45,11/70 thing? > > Thoughts? > C > > (Yes, I could build a regulator to take the 30 volts between +15 and > -15 and create an independent 20 volts. Maybe. Likewise I could > generate -5 from the -15 and a 7815 regulator. Maybe.)

I'm sorry, on the memories, I went to look at my old notebook form that era, but it seems some pages have fallen out over time :-) I think a friend has an 11/05 or 10, I will ask him for its configuration and see if that will help. cheers, Nigel Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, the origin of the open-source concept! Skype:? TILBURY2591nw.johnson at ieee.org On 2022-01-09 19:57, Chris Zach via cctalk wrote: > Probably. It's a 1973 version, the DD11-B is a MUD backplane, but it > seems to only have power plugs for +5,+15,-15. Looking at the MUD > specs I see there are backplane pins assigned for +20 and -5 so I > might be able to cobble something together. > > That's one of the fun things about Unibus: There were so many > different types that there was no guarantee that anything would work > in anything. I know this one worked with an RX11 because that's what I > used 30 years ago. Would it work with an RX21? Maybe. Maybe not. > > Note: I did check the DD11 and sure enough all of the DMA grant wires > are factory jumpered. I did remove the wire from one of them so I can > use either a RL11 or an RX21 but in the meantime I have a G7273 in > there along with the knucklebusters in the other slots) > > Getting this MM11-DP to work might take a fair bit of thought. I'm > guessing that the DD11-F is significantly different from the DD11-B? > > And the big question: What memories (if any) will work in a DD11-B > equipped pdp11/10? > > C > > On 1/9/2022 5:48 PM, Nigel Johnson Ham via cctalk wrote: >> I would assume that your 11/10 has the suffix -NC.? There were two >> versions, the -NC used -15V four wire memory, and the later -SC used >> +20V three-wire memory. >> >> The +20V was provided by a MUD slot (Modified Unibus Device) and >> there was usually a big red sticker in it warning to not plug a >> module in that was not wired for it. >> >> I believe it was standard in all models after the second version of >> the 11/05 -/10 >> >> I once tried to fix an 11/34 off-contract that somebody had done >> exactly that to- I gave up when I found that the +20V had been routed >> to some unobtainable ROMs on the CPU board. >> >> cheers, >> >> Nigel >> >> >> Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU >> Amateur Radio, the origin of the open-source concept! >> Skype: TILBURY2591nw.johnson at ieee.org >> >> >> >> On 2022-01-09 17:04, Chris Zach via cctalk wrote: >>> I'm working on my pdp11/10 getting it back together. One problem I >>> think I have is that the secondary memory (a Plessy 700101-100) may >>> be shorting the -15 line for some reason. Working on it, but does >>> anyone have a manual or anything like that for this kind of memory >>> board? >>> >>> Alternately, what kind of Unibus 16k memory board exists to get a >>> 11/10 from 16kw to 32kw of memory? Apparently I can't use a MM11-B >>> as it requires +20 and -5, both of which are not provided by the >>> power supply or sourced on a DD11-B backplane module. The 11/10 has >>> +15, -15, and +5. >>> >>> On a related note, where did +20 come from for Unibus and which >>> systems even supported it? Was it an 11/45,11/70 thing? >>> >>> Thoughts? >>> C >>> >>> (Yes, I could build a regulator to take the 30 volts between +15 and >>> -15 and create an independent 20 volts. Maybe. Likewise I could >>> generate -5 from the -15 and a 7815 regulator. Maybe.)