Interfacing PDP 11/05 to VT 50

Paul Koning paulkoning at
Tue Dec 1 10:55:29 CST 2015

> On Nov 30, 2015, at 9:14 PM, william degnan <billdegnan at> wrote:
> I have an 11/05 with ASR 33 for I/O.  I am using the M9970 console card to
> make the connection.  I have loaded papertape BASIC into core (16K) and it
> boots up from 000 000 to the TTY, I can type in programs, etc.
> Question - I'd like to switch over to a VT 50 in 20ma mode.  Not sure if
> this is possible based on what I read here:

I'm not sure I understand the question correctly.  That article clearly points out the 20 mA wires, and presumably that's where your ASR33 is connected.  The VT50 comes (according to the peripherals handbook) with a standard 20 mA interface, optional RS232 interface.  So it sounds like it would be a matter of finding where the 20 mA connector on the VT50 is, and plugging into that.

Interestingly enough, the VT52 is listed as supporting either kind of interface, but only one; "specify at time of order".


More information about the cctalk mailing list