Restoring an RXV21 and/or an RX02

Rod Smallwood rodsmallwood52 at
Wed Jun 8 09:33:52 CDT 2016

On 08/06/2016 13:01, Jerome H. Fine wrote:
> >Rod Smallwood wrote:
>> In my quest for a working  RX02 I'm trying to find out the best way 
>> of checking out an RXV21 and get it talking to the RX02. I have most 
>> of the standard diagnostics including XXDP.
>> The setup is an 11/83 with an RX50 and RD53.  (I can boot from either)
>> In the box is
>>           MSV11-J PMI
>>           KDF11-B
>>            RXV21
>>            RQDX3
>> They are in the order as above. The two dual height modules are in 
>> the right hand side of the back plane when viewed from the front.
>> I am unsure as if there is a utility for RXV21 among all the diags I 
>> have or  should I go in with ODT on a halted system and look at 
>> registers.
>> With the setup above I need to get the RXV21 going in order to check 
>> out the RX02.
> You did not specify the backplane.  I am going to assume
> a BA23 box.  Since both the RXV21 and the RQDX3
> are dual modules, and the first three slots are ABCD,
> you do not need (and should not have) a bus grant
> (M9047) beside the RXV21.  So while the RXV21
> is in the AB portion of an ABCD slot, the RQDX3 is
> in an ABAB or Q22 slot.  That is what is supposed to
> be the situation.  If you add a TK50, then that controller
> will be placed into the 4th slot beside the RQDX3.
> As long as the RQDX3 is immediately below the RXV21
> and the RQDX3 is working, then you should be able to
> check the IOPAGE registers on the RXV21 while you
> are running RT-11.  Either use ODT or SD.SYS if you
> are running V05.05 of RT-11 or later.
> Other than that, I can't help much with the RX02 drive.
> The only thing that I can think of is that the cable between
> the RXV21 and the RX02 is installed incorrectly.  I seem
> the remember doing that once or twice.
> Other hardware individuals can help much better that I can.
> Jerome Fine
Thanks for the reply.
Its good to know I have at least got the boards in the right order.

Well we have moved on again after a complete check of  cables and 
The DY (RX02) driver seems to have loaded and now the RX02 has started 
to respond.

If you do say DIR DY0 then drive 0 clonks even if there is a disk in the 
Same applies for drive 1.
So drive select works . Its probably looking for data from the head or 
sector pulses.
So me it seems to be down to the drive itself.

It fails with controller error 20 so I best go find what that means

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