MicroVAX-II Console Problem
During the Autumn of 1994 I was wondering around the University CAD/CAM lab
and happened to see an old MicroVAX-II sitting in the corner, looking solitary
and out of place. On further enquiry I was told I could have her for *FREE*!!!
(The University had upgraded to 5000/133 workstations from a Cluster of
MicroVAX-II's and some VS-2000's, they since have upgraded to Sparc 5's
booo!) they were gonna throw the -II in a skip!!!
I couldn't believe my luck... anyhow the configuration was:
MicroVAX-II QZ-A3, 9mb, RD53, RQDX3, RX50 in a BA23 and a host of
spare/additional cards including a TQK50 (but no TK50 alas),
VMS 4.7 on 40 floppies... (more stable than Windows 95 anyhow...)
also a VT220.
Taking her home sticking and placing her in bedroom, I plugged her all in... and then
finally switched all power on. A massive big Humming noise filled the room
and pretty lights flashed on the console, I then got the countdown on the
console ..4..3..2.. and then the chevron prompt >>>
I couldn't boot off DUA0 though, no OS on the RD53... a pity...
But I had a working MicroVAX-II!!! My first home VAX!!!
However before I managed to load the OS I had a problem. One time I switched
her on and whilst the countdown LED went down to zero on the back of the
system there wasn't any characters on the VT terminal. I first (wrongly)
suspected the VT220, but tested that (and the cable) elsewhere and they worked.
Finally I found (with the help of comp.os.vms) the problem. The line
driver/receiver chips on the KA630 were kaput due to a spike occurring on
the serial line from the VT220. This can occur if you switch the VT off at
the mains *INSTEAD* of at the back of terminal. Apparently VT's spiking
this way is not uncommon!!!
Although the chips blew, still the Diagnostics do not pick it up. Apparently
this is because it is non fatal as you could still login over the ethernet...
I was a bit annoyed.. it wasn't even the -II's fault!!
Moral: SWITCH YOUR VT220 OFF AT THE CONSOLE!!!!