Subject: Re: PDP-11/73 boot issues
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Aaron Jackson via cctalk writes:
Pete Turnbull via cctalk writes:
On 21/09/2021 20:34, Chris Zach via cctalk
Can an MXV11 be used in a 22 bit system? I
thought it was an 18 bit
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??
]] ERROR WHILE TESTING BOARD FUNCTIONS
]] ERROR # =001166
]] ERROR PC =040662
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
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.