10 Mar
2013
10 Mar
'13
1:15 p.m.
Hi everyone,
I recently obtained a box of stuff.
The box appears to contain a complete 11/23 boardset!
I've wanted a PDP 11 for some time, so needless to say, it would be great
to make an actual PDP 11/23 out of the boards.
What boards do you have. There will be numbers of the form 'Mxxxx' pn
the handels, thaose number will eman somethign to some people here. Of
coruse fi you know what the boards are, let us know :-)
My options appear to be purchasing a complete chassis with a backplane,
power supply, and IO-- or alternatively building my own replacements for
these parts.
What do you mean by 'I/O' ? Do you have any I/O boards in the box of
bits? IIRC the 11/23 CPU doesn;'t have an on-board serial port (is there
a version that does?), you will at least need a seiral port at he console
address. A DLV11-J is thge most commo way of doign that, in which case
you just need to make up the cable. If you have a CPU oard with on-board
seiral ports, there would be a 'bulkhead' panel for this,, but it's
really jsut swithces and conenctors and cab be easily home-brewed.
The backplane you need is a Qbus one. The PSU is a little more than a
simple power supply, it also prvides ACLO and DCLO (basically power-OK
signals) and a line-time clock (at twice mains frequency IIRC). It _can_
be homebrewed, but Qbus boxes/backplaens/PSUs are not that rare, and
jsut about any one can work, possibly with very minor modifications.
The backplan e is just connecotrs, no logic. The main problem in making
one is gettign the right conencotrs (DEC used 18-pins-on-a-side, double
sided, 0.125" pitch conenctors). Normally if you need such conenctors for
a custmo job the easiest way is to raid them form a spare backplane,
shich sutggests the backplanes are easier to find than the conencotrs.
And qhile there are many times of backplane, plain Qbus ones are among
the most common.
I'd also need a disk at some point, but for now that's out of scope.
Do you have a disk controller PCB in the box?
-tony