PDP 11/03

Noel Chiappa jnc at mercury.lcs.mit.edu
Mon Nov 9 16:05:58 CST 2015

    > From: Henk Gooijen

    > As far as my limited PDP-11 knowledge goes, none of them used
    > handshake.

I'm pretty sure this is true of all the ones that had a hardwired serial
console - it's definitely true of the 11/23 and J11 chip ones (/73, etc), and
probably the 11/03's too (although it's been 30+ years since I used one of
those, so don't hold me to that :-).

    > So, Rxd, TxD and GND is all you need to connect. 

Errq, many of them _require_ a loop-back between a pair of pins on the
Berg/DuPont connector to operate - this is true of the DL11 (M7800 - UNIBUS),
DLV11 (M7940 - QBUS), DLV11-J (M8043) and 11/23+, for instance), and probably
the 11/83-84 too. So just connecting up R, X, and Gnd alone won't do it.

    > Also, common (?) is *no* parity.

That, and number of bits, I have no idea about - we always changed things to
our local standard (8 bits, no parity, 2 stop bits, IIRC) straight away. Best
to check the hardware, and see what it's set to, and either set it to what
you're using, or change what you're plugging into it to match.


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