Re: Running NetBSD on a VAXstation 3540

We uncommented the 3540 code in the bootloader and kernel, copied the updated files to the SCSI disk, and tried booting again. The only thing that we see is:

CPU0B >>>boot dka0
VMB V1.0
-DKA0
..
...

Our next step is to modify the bootloader to load a unique flag into R1 and halt the processor periodically. The next time we try to boot we expect to see the processor halt. We can use the console EXAMINE command to see the contents of R1 and see the progress in the bootloader. We can use the console CONTINUE command to continue running the boot loader until the next halt instruction. This should let us narrow down why we don't see any messages on the 3540 console.

On Sun, May 3, 2026 at 8:25 PM Michael Thompson <michael.99.thompson%gmail.com@localhost> wrote:

The Rhode Island Computer Museum has a VAX 3540 currently running OpenVMS 7.3.

We would like to run NetBSD on this system. We used a VAX 3900 Simh to install NetBSD 10.1 on a disk image, copied the image to a SCSI disk drive, and tried to boot it on the 3540. This was displayed on the console:

CPU08 >>>boot dka100
VMB V1.0
%VMB-F-ERR, PC = 000008EF
%VMB-I-STS, R0 = 000001A4
CPU08 ?06 HLT INST
CPU08 PC = 000010DE
CPU08 Failure.
CPU08 >>>

So it looks like there is something in the 3540 hardware that the generic kernel doesn't understand. The same disk works fine in a VAX 3100 M38. We also tried a NetBSD CDROM with the same results. We have not set up a MOP boot server yet to try that.

We would like to add support for the 3540 to NetBSD. What would you recommend as a way of finding out where the kernel died?

--
Michael Thompson