8 Mar
2015
8 Mar
'15
9:03 a.m.
On 3/7/2015 10:38 PM, Earl Evans wrote:
Hello fellow DEC enthusiasts,
I have a BA11-N mounting box with Q18 9-slot quad-height backplane. The
power supply is toast. My goal is to hack it into something useful.
I'd like to replace the power supply with a sufficiently-powered ATX PSU.
I've read the instructions at:
http://www.diane-neisius.de/pdp11/index_E.html#atx
However, unlike the DEC PSU, the ATX power supply won't supply a 60 Hz line
time clock (LTC) signal to the backplane via BEVENT. So, my question - has
anyone used a standard ATX PSU for a PDP-11 QBUS system, and if so, how'd
you work around the LTC issue?
Once I solve the power issue, I have 11/23 CPU cards, RAM, and SLUs galore.
I'm not planning to make this very power hungry though.
Thanks!
- Earl
Earl, I did an ATX conversion on my
BA123 to dual 500W ATX PSUs. I used
Brad Parker's QBus POR device for
generating the LTC, but am not sure on
current availability as past emails to
him have gone unanswered.
http://www.heeltoe.com/index.php?n=Pcbs.Qbus-por
A trick is that his LTC output is open
collector, thus needs a pullup unless
your backplane provides.
- J.