RX02 Debugging

[Lyle Bickley]

On Tue, 02 Aug 2016 21:43:03 -0700
Kirk Davis <kirkbdavis at me.com> wrote:

> Thanks for the suggestions. I’m in Sunnyvale, CA.
> 
> I actually got the rx02 from another hobbyist that
> used it with the 44 in 2008 so I suspect it is configured correctly.
> The other drive doesn’t have a belt so I’m unable to test with it.
> I’ve verified the cable direction. It’s a sweet 44 - super clean,
> runs great and is like a tank.
> 
> One of the problems is I don’t know normal behavior of the drive. The
> motor is aways spinning for unit 0. When I try booting I don’t hear
> the heads load or seek. I’m new to the 44 monitor commands & boot
> process etc so I’m learning as I go.

The motors always spin. The heads should engage whenever selected.
You;ll hear a serious "clunk" when they load.

If you're coming to the VCF this coming weekend, Bob Rosenblum and I
will have a running RX02 attached to a PDP-8/M. You can hear all of
it's "sounds" there. You'll also be able to play "Spacewar!" with our
VC8/E and XY monitor, etc.

BTW: Make sure you have the correct switch settings on the RX02
mainboard for your PDP-11...

> I’m also making one of these to help isolate if it’s a
> drive/cable/controller problem:
> 
> http://www.torok.info/computing/pdp11/rx02/index.htm

That looks like a cool project. Would like to see it when you've got it
running!!!

Lyle

> > On Aug 2, 2016, at 3:24 PM, Paul Anderson <useddec at gmail.com> wrote:
> > 
> > Hi KIrk,
> > 
> > The H771 is a rock solid power supply. I never saw one go bad while
> > in field service, but they are getting old. Checking the output
> > voltage and ripple is not a bad idea.
> > 
> > forgive me for asking, but where are you located?  The RX02 had 4
> > different power hanesses for i20, 220, 50 hz and 60 hz. Also
> > different belts amd pulleys.  if any of this is wrong you cn see
> > weird problems. A lot of RX02s and replacement drives were soul
> > through brokers who never asked or were never told where the unit
> > was going.  if you aren'y useing 120/60 that would be my first
> > thought.
> > 
> > Is the problem the same when booting off either drive?  Also check
> > the switches and the resistors on the head cables.
> > 
> > Good luck, Paul  
> 
> > Jerry Weiss wrote:
> >
> >If you haven’t already, check the cable seating, orientation and for
> >bent pins.   
> > On the RX211 board J1 - TT is the location of the AC LO - Active
> > Low signal.
> > 
> > On Tue, Aug 2, 2016 at 4:06 PM, Kirk Davis <kirkbdavis at me.com>
> > wrote: 
> >> I’m a noob using RX02’s but thought I’d run this past people that
> >> may have debugged them in the past and see if they agree with what
> >> I’m finding:
> >> 
> >> I’m trying to get a RX02 + RX211 + 11/44 going. The RX02 appears
> >> to power up OK (fan and motor spinning). I verified I have the DY
> >> boot rom in the 44. Attempt booting from the console:
> >>   
> >>>>> b dy  
> >> 
> >> S
> >>  17777707 173436
> >> 
> >> Which halts in the DY boot rom. I look at the base RX211 register:
> >>   
> >>>>> e 17777170  
> >> 17777170 104040
> >> 
> >> From the manual this like the controller is present but the high
> >> order bit is set indicating an error
> >> 
> >> Looking at the status register;
> >>   
> >>>>> e 17777172  
> >> 17777172 000010
> >> 
> >> Bit 3 == RX AC LO - This bit is set by the interface to indicate a
> >> power failure in the RX02 sub- system.
> >> 
> >> So start looking at the RX02 power supply?
> >> 
> >> 
> >>   
> 



-- 
73      AF6WS
Bickley Consulting West Inc.
http://bickleywest.com

"Black holes are where God is dividing by zero"