Introduction and need help bringing some pdp11's back

Chris Zach cz at
Tue Oct 29 11:28:25 CDT 2019

Hi all!

Re-subscribing to this list after a 20+ year "vacation" while raising 
kids. I was pretty active in the Dec pdp10, pdp11, and pdp8 communities 
back in the 80's and managed to acquire a lot of "stuff". Now that I 
have some time and space again I'm looking back into the pile of "high 
mass hobbies" and wondering what still works.

In terms of communities I see the pdp8-lovers list is still going but I 
can't seem to find the pdp11 email list anymore. If anyone can add me 
I'd appreciate.

On to the technical issues: I currently am trying to bring back online a 
PDT11/150 and my main Q-Bus pdp11/73. The 11/150 is trying to boot but 
it looks like my old disk with RT11 5.1 and the PD: boot driver is no 
longer working. Does anyone have a copy of RT11 5.1 source disks they 
can loan me (I can't find my set).

The 11/73 is a bit more interesting: It's an 11/73 quad height CPU, 4mb 
of ram on a single DEC Q bus card, and for storage has an MTI ESDI 
controller hooked up to a Fujitsu ESDI drive. After some workings I was 
able to get the controller back online (hint: The password to get into 
the controller to make changes is MTI) and while I can boot RT11 off one 
of the two partitions my RSX11M 4.0 generated instance is flunking with 
a boot error. Probably some disk rot.

I also have a RLV12 controller in it and a pair of RL02's sitting in a 
closet here that I can drag upstairs with RSX111M 4.1 on them. Better 
than nothing and might allow me to boot up and possibly run a disk 
repair/regenerate the boot code on the EDSI disk. But that's not the 
real problem.

The real problem is I'm trying to put an RQDX3 in there instead of the 
ESDI controller so I can boot off RX50's. And I have no idea which way 
all the various ribbon cables are supposed to go. Will any 50 pin cable 
work between the RQDX3 and the BA23 distribution bulkhead? Anything 
special about the 34ish pin cable that goes between the bulkhead and the 
RX50? So far when I try to boot all devices DU0-3 give me not yet ready.

Ultimately I would like to format one of my MFM Maxtor drives as a RD54, 
then install MicroRSX and MicroRSTS from floppy. For the big ESDI drive 
I'd be happy getting that upgraded to RSX11M+ if I can find install 
media and running it as a serious system.

I also have TK70's, and a couple of other oddball things here including 
all the parts for BLT.AI.MIT.EDU (Sometimes called LSD), a RM80, an RX02 
with a RXV11 controller, and a bunch of other weird stuff.

Anyway, will be interesting to see if I can get these going. If I can 
get the 73 running the next step would be to get the 11/24 up and going, 
then start working on the 2020...


On 10/29/2019 11:27 AM, Jon Elson via cctalk wrote:
> On 10/29/2019 09:45 AM, jos via cctalk wrote:
>> an IBM 4331 for 1000 Euro b.i.n. seems OK to me, if I was in that sort 
>> of thing !
>> See and his 
>> other offerings...
> WOW, this is some amazing stuff he has!
> Jon

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