VAX4000 VLC diagnostics/console

Doc Shipley doc at
Wed Jul 14 21:42:06 CDT 2021

On 7/13/21 14:30, Adrian Graham via cctalk wrote:
> Hi folks,
> Powering up with nothing attached apart from an MMJ/H8571 cable I get
> nothing on the console, I'm using PuTTY via a genuine COM1 port on a PC
> which is one level above what I used last time I powered the machine up
> (FTDI USB adapter to a laptop). Diagnostic LEDs cycle through the tests and
> end up at '1111 0011' which according to the manual is 'entering the
> console program'.
> Clearly the DALLAS has passed the TOY tests, but if it's not happy would
> that stop the console displaying? It doesn't matter how I set S3, next step
> I guess is to hook it up to a 'proper' VT.

   Adrian, I'm having exactly that problem with my VLC.  I put a Real 
VT420 on it and still get no output. With a known-good/compatible 
monitor and keyboard on it, same thing.

   If there's a solution to this, I'd love to know.


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