[Info-vax] VAX RDMs (Remote Diagnostic Modules)

[Johnny Billquist]

On 2011-11-16 18.09, Henry Crun wrote:
> On 16/11/11 17:11, Bob Koehler wrote:
>> In
>> article<272ef8f8-4d9b-4950-99e0-a50e0e7886b7 at b32g2000yqn.googlegroups.com>,
>> vaxorcist<vaxorcist at googlemail.com> writes:
>>>
>>> Surely a modem, but what else? Another RDM or a special module or
>>> computer for
>>> remote diagnosis?
>>
>> Could have varied, but an LA36 ahrd copy terminal would have been
>> sufficient.
> Actually I seem to recall (could be wrong, though) that LA36's were
> current loop, and could not talk to a standard modem. You would probably
> need an LA120, or (slower) LA70(?)

I think both LA36, as well as LA120 came in different flavors. You'd 
(obviously) need one with RS-232 (or EIA as it used to be called).

I have used LA120 with both types of interface, and it has been a case 
of either-or in all of them.

> I remember the RDM on a PDP 11/70 - DEC could only dial in if we
> switched from local to remote console (IIRC a rotary switch on the front
> panel)

Yup.

	Johnny