11/34 up! (sort of)

[Jacob Ritorto]

Thanks, Jon.  I tried this simple test via the front panel.  It wrote and
read back the memory perfectly, just as I'd entered it.

On Wed, Jan 28, 2015 at 11:49 PM, Jon Elson <elson at pico-systems.com> wrote:

> On 01/26/2015 09:42 PM, Jacob Ritorto wrote:
>
>> Woohoo, I finally, after over a decade of being somewhat out of the pdp11
>> hobby, have managed to bring back to life one of my pdp11/34s!
>>
>> It's a plain 11/34 with dl11-w, ky11-lb, ms11-L, rl11 and a M9312
>> terminator/boot rom board.  I have an emulex controller and some fuji 160s
>> I'll tack on later so I can run 2.9BSD once I get the basic build
>> confirmed
>> safe.
>>
>> It's not in great shape at the moment, apparently, as these xxdp 2.5 diags
>> are crashing left and right.  But it at least boots the os and tries.
>>
>> I initially had, but mysteriously lost the console emulator/ODT
>> functionality, seems it's starting at 165000 instead of 165200 at poweron.
>> Maybe a 9312 switch mis-set...  So I'm booting from the panel by calling
>> the address of the ODT or the rl02 boot rom, which does the trick.
>>
>>
>>
>>  Thinking about this problem, I'm wondering if one of the address bits is
> stuck?
> I'm guessing since 165200 seems to work better than 165000, that maybe the
> 200 (octal) bit is stuck on?  You could try depositing 1234 to location 0,
> and
> 4321 to location 200, and then read back both locations.  If they both read
> 4321, then probably that address bit does not change as the CPU is
> commanding it to.  It is also possible that the diag/ODT ROM is not
> properly
> sensing the address bits on the Unibus.
>
> Jon
>