Vaxstation 3100 - I have console access

Peter Coghlan cctalk at
Thu Feb 18 09:22:56 CST 2016

> Peter,
> Thanks for the email.  My challenge is that this machine has a floppy and a
> SCSI drive (both appear to be cabled correctly when I open things up) and
> yet neither show up when I do a "show device" from the console.
> >>> show device
> -------  ------  --------  ------  --------  -----  --  ------  ---
> ESA0     SE0     08-00-2B-16-58-20
> Therefore, when I issue a "boot" command, it's trying to boot from the
> network and not from the floppy I currently have inserted.
> Any ideas on troubleshooting I can do to determine why it isn't seeing
> things on the SCSI bus?  (I'm assuming this is a SCSI floppy - please let
> me know if I'm incorrect in that assumption.)

Hi Bryan,

Now that you mention it, your TEST 50 output (quoted below for reference) is
not showing any SCSI controllers.  There ought to be either one or two of
them, depending on the model.

> KA42-A  V1.3
> ID 08-00-2B-16-58-20
>    MONO     0000.0001
>  ? CLK      0000.0005
>    NVR      0000.0001
>  ? DZ       0000.4001
>       00000001 00000001 00000001 00004001 00000000 00000000
>    MEM      0010.0001
>       01000000
>    MM       0000.0001
>    FP       0000.0001
>    IT       0000.0001
>    SYS      0000.0001
>    8PLN     0000.0001  V1.3
>    NI       0100.0001
> >>>

As far as I recall, some of the 3100s have a the floppy connected to a SCSI
controller but others have a non-SCSI floppy controller like the one in the
VAX 2000 which I think shows up as DUA2 instead of DKAsomething.

Have a look at the where the SCSI connectors go - it might be to a daughter
board in the top corner.  There may be one or two 40 pin NCR5380 SCSI
controller chips on it.  Check that this board is correctly connected to the
system board - it probably sits directly into a couple of connectors on it. 
If there is a cable instead, make sure it is plugged in properly.  If you are
good with a multimeter, check that it is getting power.

I hate to say it but I have a Microvax 3100 (rather than a VAXStation 3100)
which has failed in a similar manner - both SCSI controllers are not visible.
They are on the system board though, not on a daughter board.  I doubt both
failed independently - probably some support circuitry they have in common.

If you can't get the disks working, it should still be possible to boot the
operating system of your choice over the network if you have a suitable boot
host (which might not have to run the same os) or emulator.

Peter Coghlan.

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