On 8/14/18 5:40 PM, Josh Dersch via cctalk wrote:
On 8/14/2018 2:12 PM, Ethan Dicks via cctalk wrote:
On Sun, Aug 12, 2018 at 11:36 PM, robertbeauchamp33--- via cctalk
<cctalk@classiccmp.org> wrote:
My mother is moving and her spouse has a MicroVax I he bought new
back in 1984 for some crazy amount. I don’t see this model listed in
your chart? Can you tell me if there is any value to this machine?
He also has two original monitors.
There is some value, since it's in a BA23 and _is_ a VAX, even as slow
as can be. They are somewhat uncommon because they were only
available for a couple of years unlike most other DEC machines.
Having used one in the mid-80s when they were brand new (and $10,000),
they are quite slow and painful and limited to, I think, various
versions of MicroVMS and VMS 4.x, depending on disk size (MicroVMS
fits on a 30MB disk when the full version would not). I don't recall
if there is any support for them in VMS 5.x - the max RAM is 4MB
(unlike later Qbus VAXen, the RAM is _on_ the Qbus) but one could
easily put a newer disk controller in there other than the RQDX1 and a
larger disk.
Be aware that most (if not all?) QBus SCSI controllers appear to be
incompatible with the MicroVAX I. I'm not entirely sure why this is,
but none of the Emulex, CMD, or Dilog controllers I've tried are
listed as compatible with the system -- they all state compatibility
with the II and later .I've tried using them in my MicroVAX I with no
success. VMS fails to boot, and Ultrix kernel panics. Not to hijack
the thread, but does anyone have any idea why this might be? I'd like
to get the system doing something interesting and not having to rely
on very old MFM disks would be nice...
- Josh
No personal experience here, but the Emulex UC04 is listed as MicroVAX I
compatible. See
https://ia801902.us.archive.org/11/items/bitsavers_emulex1987_5921218/1987_catalog_text.pdf
page 27.
The UC07/UC08 is documented not to support the MicroVax I due to lack of
Scatter/Gather support. See
https://ia801902.us.archive.org/11/items/bitsavers_emulex1987_5921218/1987_catalog_text.pdf
Section 1.6.3 Page 1-22.
Having no Scatter/Gather (aka Qbus IO Map) is not a surprise as the
MicroVax I only uses Qbus Memory directly. Thus mapping to a larger
physical address space should not be needed (micronote #22). However, I
don't follow what changed to lose support on the UC07/08.
Jerry
