VAX4000 VLC diagnostics/console

Zane Healy healyzh at
Tue Jul 13 14:39:13 CDT 2021

As far as I can tell, the VLC and Model 60 will boot with a dead DALLAS chip, the Model 90 *WILL NOT* (it hangs on the tests).  Having said that, I think you need to leave the VLC plugged in for a bit.  It took 2-3 tries to get things going.

When I did all my testing about a month and a half ago, I used a VT320.  I’m not sure if I’ve ever tried to talk to a VAXstation with anything other than a DEC terminal.

I swapped out my VLC and Model 90 SCSI drives with SCSI2SD boards, I still need to do that with one Model 60, and one AlphaStation.


> On Jul 13, 2021, at 12:30 PM, Adrian Graham via cctalk <cctalk at> wrote:
> Hi folks,
> I'm testing a little BlueSCSI adapter (BlueSCSI <>) which
> while being aimed at 68K Macs should also work as an 8 bit target for older
> VAXen, it's a newer cheaper SCSI2SD solution and I should point out it
> works as intended on a Mac Plus so the module itself is fine.
> Nobody appears to have tested on small VAXen yet so tonight I dug out my
> VLC to give it a go.
> 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.
> Cheers,
> -- 
> Adrian Graham
> Owner of Binary Dinosaurs, the UK's biggest private home computer
> collection?
> t: @binarydinosaurs    f:
> w:

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