Subject: Re: MicroVAX I: in need of modern OS.
To: Brian D Chase <>
From: Matt Thomas <>
List: port-vax
Date: 02/04/1999 20:34:09
At 01:20 AM 2/4/99 , Brian D Chase wrote:
>After a certain amount of struggling, I've managed to get an old MicroVAX
>I up and running to a >>> prompt.  It looks like the RD52 is dead, or at
>least missing any sort of OS.  The system does have an RX50 which I still
>need to test out with some boot media. 

I have a uVAX I as well.  It has two RD52s running Ultrix 1.2m (at last boot
which was about a decade ago).  It has 4MB, a RRD50 CD-ROM, a RQDX3, a DZQ-11,
and a DEQNA.  I haven't turned it on since I'm worried about blowing the breaker
in the room. :-)

>According the VAX Arch Ref Manual, the MicroVAX I processor actually
>includes the CMPC3, LOCC, SCANC, SKPC, and SPANC string instructions which
>are omitted in the MicroVAX II.  I suppose that good news :-)  Anyway, I'd
>like to see NetBSD/vax support this processor.  It would be the slowest
>VAX CPU to support NetBSD/vax to date.  In fact it's likely to be the
>slowest CPU capable of supporting NetBSD aside from maybe the 11/730. Both
>the 11/730 and the MicroVAX I run at 0.3 VUPS.  According to the DEC specs
>I've seen, this is about the same speed at which the lowly MicroPDP-11/53
>runs.  I don't know, with the recent addition of the VS4000/60 it just
>seems like we should also expand a little into the slower systems.

The problem with the uVAX I is that it runs using the Q22-bus as its
main system bus.  There are no mapping registers so all DMA either needs
to be bounced or has to support scatter/gather directly.

>I don't know if the MicroVAX I supports MOP booting or not.  It seems like
>it's so old they might not have been thinking about such frivolous
>features as netbooting. I do have a 4Meg memory board in the system, so it
>should be in relatively good shape wrt resources for running NetBSD.

I seem to remember that there's no autoboot from XQA0 but it could
boot from it via the >>> prompt.
Matt Thomas               Internet:
3am Software Foundry      WWW URL:
Sunnyvale, CA             Disclaimer: I avow all knowledge of this message