RX02 Debugging

[Kirk Davis]

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.

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

Kirk



> 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?
>> 
>> 
>>