Thanks for the links, but I already have the config data, it was only the engineering drawings that I lost after I left the DEC business!
The 11/23 you supplied was originally configured to power up through 24, indicating it was used on a battery-backed-up system, so I changed that one to go directly to ODT. I got an 11/73 from another collector and left that one to power up to 173000. I know from years of experience as an FE and running a production line that an 11/23 will not work without bank zero memory, hence the title of this email chain. So while I appreciate everybody's help, there is no point in scratching your heads! If I cannot find any data on the Plessey memory I will just have to look for an MSV11-DD or something to give me at least some memory to start off with! cheers, Nigel The 11/23 you supplied was On 2021-10-23 1:34 p.m., Josh Dersch wrote: > On Sat, Oct 23, 2021 at 10:30 AM Josh Dersch <dersc...@gmail.com > <mailto:dersc...@gmail.com>> wrote: > > > > On Sat, Oct 23, 2021 at 10:12 AM Nigel Johnson Ham via cctalk > <cctalk@classiccmp.org <mailto:cctalk@classiccmp.org>> wrote: > > It is not possible to get ODT running without bank 0 memory. > All I get > is output of 173000 and the no ability to input. > > > How is your CPU board configured? Based on the above, it sounds > like it's set up to jump to a ROM bootstrap at power-up (at > 173000) and I'm guessing given your current configuration that > there isn't one. Without memory present/functional, this may be > confusing things further. There are jumpers on the 11/23 CPU to > select what the CPU does at power-up (see: > https://gunkies.org/wiki/KDJ11-A_CPU > <https://gunkies.org/wiki/KDJ11-A_CPU>). Try setting it to drop > directly into ODT instead. > > > Sorry, just realized I pasted a link for the 11/73 CPU config (same > basic idea, though). Try this instead: > http://www.willsworks.net/pdp-11/boards#KDF11-BA > <http://www.willsworks.net/pdp-11/boards#KDF11-BA>. > > - Josh > > > > - Josh >