Microvax II 'primer'?

[Warner Losh]

On Sun, Jan 21, 2018 at 3:50 PM, Warner Losh <imp at bsdimp.com> wrote:

>
>
> On Sun, Jan 21, 2018 at 3:04 PM, Rob Jarratt via cctalk <
> cctalk at classiccmp.org> wrote:
>
>>
>>
>> > -----Original Message-----
>> > From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Jules
>> > Richardson via cctalk
>> > Sent: 21 January 2018 19:26
>> > To: xx Classiccmp mailing list <cctalk at classiccmp.org>
>> > Subject: Microvax II 'primer'?
>> >
>> >
>> > So, I picked up (and I did just carry it into the house, and now I
>> hurt) a
>> Microvax
>> > II from another list member yesterday. Cosmetically it's a disaster
>> (BA123
>> has a
>> > cracked top panel, broken wheels, missing front door, missing right-rear
>> panel)
>> > but internally it appears to be complete; board wise we have:
>> >
>> >    M7606 - CPU
>> >    M7608 - 4MB ram
>> >    M9047 - grant continuity
>> >    M7504 - DEQNA ethernet
>> >    M3104 - DHV11 8-port serial
>> >    M7555 - RQDX3 disk controller
>> >    M7546 - TX50 controller
>> >
>> > ... it's got a TK50 and hard drive (no idea of capacity).
>> >
>> > Operational status is a complete unknown, and I have absolutely zero
>> > knowledge about these systems - so my question at this stage is what
>> > background reading I need to be doing in terms of pre-powerup* checks,
>> > actually hooking a console, if there's a suggested minimal config I can
>> use to
>> > diag the CPU, and then (assuming it gets to that point) how to actually
>> use the
>> > thing (I'm assuming it was running VMS rather than Ultrix, but I don't
>> know for
>> > sure). I'm wondering there aren't any handy tutorials out there,
>> alongside
>> > whatever DEC docs are recommended.
>> >
>> > * e.g. for most machines I'd be thinking in terms of pulling all
>> boards/drives,
>> > hooking up a dummy load to whatever PSU rails required it, and then at
>> least
>> > running the PSU up in isolation first, but I don't know to what extent
>> this
>> > machine requires some logic in place for the PSU to even run.
>> >
>> > cheers
>> >
>>
>>
>> You might find that the filter capacitor goes up in smoke soon after you
>> connect the PSU to the mains, even without powering it on. It doesn't
>> actually do any damage and the PSU will continue to work (assuming it is
>> just the filter capacitor). Check it, it is likely cracked and will soon
>> go.
>> If I remember correctly there are actually two of three of these (marked
>> "RIFA"), it is probably a good idea just to replace them before they go.
>> Otherwise it is certainly wise to check the PSU visually for any obviously
>> failed electrolytics. If  you have one of the DEC load boards you could
>> connect the PSU to that as a dummy load. I don't think there is much in
>> the
>> way of dependency on the CPU to run the PSU.
>>
>> Once you have the machine up and running the easiest thing to do is to
>> boot
>> it over the DEQNA by setting up a cluster on SIMH and making your MicroVAX
>> II a satellite. I am not sure if 4MB is enough to do that though. Go with
>> a
>> 5.x version of VMS as I believe later versions may not support the DEQNA.
>>
>
> Doh! Hit send too soon:

The website http://antinode.info/dec/deqna_settings.html says


> The DEQNA is obsolete (even by Q-bus standards), troublesome
> <http://antinode.info/dec/deqna_settings.html#Troubles>, and not
> supported by VMS
> <http://antinode.info/dec/deqna_settings.html#VMS_Support> since about
> V5.4. A compatible card, the DELQA
> <http://antinode.info/dec/delqa_settings.html>, replaces the DEQNA.
>

the rest is me


> I was going to say VMS 4 is a better bet since 5 removed support, but
> looks like 5.4 is the last version with support. Though the MicroVAX is UP,
> so you might be better off with VMS 4 instead of VMS 5.
>
> Warner
>