VAX4000 VLC diagnostics/console

Antonio Carlini a.carlini at
Tue Jul 13 15:16:46 CDT 2021

On 13/07/2021 20:30, Adrian Graham via cctalk wrote:
> 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.
My VS4000-60 has a DALLAS chip that is either dead or not working very 
well: it will not remember settings at all. It boots fine using a VT420 
and it also boots fine with a monitor/keyboard connected.

Do you get *any* output on the console at all?

The easiest thing to try would be a known good VT terminal, then you 
don't have to worry about the H8571-? being the correct "-?" for your 
config (ISTR that there are a number of variants, each subtly different).


Antonio Carlini
antonio at

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