I have been through the ground up restoration of a full chassis version, make sure the CPU is functioning correctly first. The best place to start:
http://www.psych.usyd.edu.au/pdp-11/hints.html Try toggling in the "Line Time Clock Interrupt Test" from 001000, returned the expected value of 000104. Here is a pdf of the cabling for tty console, if you have no current loop device an rs232 converter will work. http://vintagecomputer.net/teletype/asr33/M9970_TTY.pdf See also http://www.pdp-11.nl/pdp11-05/cpu/boards/m7260.html echo characters toggle-in program 005000 CLR R0 105737 TSTB @#177560 177560 100375 BPL -3 105737 TSTB @#177564 177564 100375 BPL -3 113737 MOVB @#177562,@#177566 177562 177566 105737 TSTB @#177564 177564 100375 BPL -3 110037 MOVB R0,@#177566 177566 105737 TSTB @#177564 177564 100375 BPL -3 000756 BR -16 On Sun, Sep 27, 2015 at 4:47 PM, tony duell <a...@p850ug1.demon.co.uk> wrote: > [Second serial port on a PDP11/05] > > > Curious: what if the built in one were > > faulty, or if you wanted to use rs-232 > > instead of current loop? > > IIRC the 11/05S has a way to disable the built-in > console port (fit a wire link on one of the boards?) > the original 11/05 doesn't. There must be a way to do > it by cutting/jumpering but it is a mess.... > > Therefore, if the built-in port is faulty it is going to be > a lot less work to fix it than to disable it and add a DL11 > Heck, the entire 11/05 CPU is only a couple of hundred ICs, > the serial port is going to be a small fraction of those. It is > not going to be hard to figure out. > > As for the physical interface, firstly the OP mentioned a > teletype, which to me suggests current loop anyway. If > you need RS232 then either pick up TTL level signals on > the CPU board and add level shifters (very easy, but > makes the machine not original) or make a current loop > to RS232 interface (not exactly difficult either). I think > both are less work than disabling the built-in port. > > -tony > > > > - John > > > -- Bill vintagecomputer.net
