No subject - test-drb@ccmp.vtda.org

23 Sep 2021

Subject: Re: PDP-11/73 boot issues
References: <87ilytoikj.fsf at carbon.nat.rhwyd.co.uk>
<CADBZjLYN9aUTDHJ6=XJwNnNefTUbzyZis4evRS1Coy2r9xcX5w at mail.gmail.com>
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at alembic.crystel.com> <21789e85-2aa4-3b61-db31-b21fd8c08a03 at
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Aaron Jackson via cctalk writes:

...
  Pete Turnbull via cctalk writes:

  On 21/09/2021 20:34, Chris Zach via cctalk
wrote:
  Can an MXV11 be used in a 22 bit system? I
thought it was an 18 bit
 device? 
 MXV11-B is 22-bit.  MXV11-A is 18-bit but supposedly can be used in a 
 22-bit system if the RAM is disabled. 
 Yeah this is a 22 bit card. Josh sent me an xxdp image which I could
 easily boot from my scsi2sd (thanks!).  Seems to be reporting an error
 with the CPU unfortunately:

 ]] .R ZKDJ??
 ]] ZKDJB2.BIC
 ]] 
 ]] ERROR WHILE TESTING BOARD FUNCTIONS
 ]] ERROR # =001166
 ]] ERROR PC =040662
 ]] 043632

 This happens regardless of whether W9 is installed or not (supposedly
 disables the LTC register on the CPU?)

 I'll see if I can borrow another CPU card form a friend this
 weekend. Unless anyone else has any ideas?  Another suggestion on IRC
 was to disable the PSU LTC and enable the LTC on MXV11 but will need to
 look up some details on how to do this. 
Had a nice cycling trip this evening to pick up a spare 11/73
card. Unfortunately it did not fix my issues so I'll have to do some
more digging.

Has anyone disconnected the BEVENT line and used a signal generator to
provide the LTC? Curious to try this to figure out if mine is just being
noisy or something.

Thanks,
Aaron