Re: Help about installing NetBSD on a VAXstation 4000/90 (Cougar)

[Felix Deichmann <m4j0rd0m0%gmail.com@localhost>]

Am 03.05.2018 um 14:17 schrieb Silas:
> I was sure S3 was at the right position until I talked to Ragge. The 
> button is sunken and I cannot change it.  A picture here: 
> http://silas.net.br/tmp/s3.jpg

I have seen many of these switches in bad condition, no idea why people
think they must use brute force to toggle them... :)

> What I thought before:
> 
> * The LCSPX card is faulty and nothing appears on the console.  If I 
> remove the card I can access SRM via the console -> so S3 switch 
> might be at the right position.
> 
> What I'm thinking now (after investigation and sugestions from 
> Ragge):
> 
> * The S3 switch might be at the wrong position and that is why I 
> don't get any output from the console if I have LCSPX plugged in. If
>  I remove the LCSPX card, the system falls back to console as default
>  input/output device and that is why I can access SRM via console.

You probably nailed it.

> I'm in the process of reading the VAXstation 4000/90 documentation 
> and see if I can override the S3 button state somehow.

Interesting point. Look for 16-bit "Configuration Register" (CFG) at
physical address 0x25800000. Bit 3, ALCON, reflects the "Alternate
Console" S3 switch, and is 1 when the serial console is to be used. See
KA49 Processor Module Specification V 1.1, chapter 5.2.
However, the CFG register is described as read-only!

Cheers,
Felix