Looking for info on memory

[Nigel Johnson Ham]

Ah, well there you see the end of my technical knowledge.

When the 11/83 came out, I was already a manager :-)

Thanks for the info, I will try it and report back!

cheers,

Nigel

ps, No way is it PMI mmeory, it is waaay too old!


On 2021-10-19 11:03 p.m., Chris Zach via cctalk wrote:
> It can be done, technically the 11/83 and 11/93 put the CPU in slot 3
> with the PMI memories in slots 1 and 2. Putting the CPU in slot one
> with the PMI memory in 2 and 3 would just cause all memory access to
> slug across the Q Bus.
>
> So you can leave slots 1 and 2 open if you really want to, makes it
> easier to deal with possible PMI screwage (I always wondered if one
> could put a CPU in slot 1, then the M8013/8014 RL01 controller in
> slots 2/3 but I don't remember if the 813/8014 will work in a 22 bit
> unit without catching fire or something).
>
> Anyway, just try running the CPU in slot 3, then the memory in slot 4,
> and the DLV11J in the right side of slot 5. That would simplify things
> as much as possible.
>
> C
>
> * PS: Right now I'm running my 11/83 in slot 1 with a 2mb PMI memory
> board in slot 2 and the TK70 controller in slot 3. The reason is that
> the PMI memory board is from an 11/84, and it has the bug that
> prevents it from working properly in a true Q Bus system.
>
> I *think* the bug is related to concurrent memory access from both the
> Q Bus DMA and PMI bus as just using the memory as a Q Bus memory has
> no problems. A true 11/84 works because there is nothing on the Q-Bus
> as all memory access is done through the Unibus bridge thingie which
> only does memory transfers on the PMI bus (it's not a true Quniverter
> for DMA purposes).
>
> I also *think* the bug is related to burst mode DMA as I have run my
> ESDI controller in normal DMA mode (slower) with the PMI memory
> running as PMI without problems. However if I turn on burst/hog mode
> DMA it will crash RSX11 (but not RT11). Go figure.
>
>
>
> On 10/19/2021 8:50 PM, Nigel Johnson Ham via cctalk wrote:
>> In all the hundreds of systems I have shipped, I have never put the CPU
>> in slot 3! I was VP Operations of Transduction, DEC's biggest components
>> group OEM in Canada.
>>
>> No, I don't know if the CPU is good (it is a dual-width KDF11-A btw),
>> but it is in slot 1 AB with a DLV11J in slot 2AB.  The memory has been
>> in slot 3 as well as lower.  Since there is nothing above or below it on
>> the CD side there cannot be any interference in the CD connectors.
>>
>> I do have an 11/73 dual width board arriving tomorrow so will see if I
>> get the same results with it.
>>
>> Thanks for reading,
>>
>> Nigel
>>
>>
>> On 2021-10-19 7:55 p.m., Chris Zach via cctalk wrote:
>>> Hm, ok all my Plessy boards are dual height, 1mb boards. Are you sure
>>> the 11/23+ is working, and do you have the CPU in slot 3 with the
>>> memory board in slot 4 (staying away from the PMI slots)?
>>>
>>> C
>>>
>>> On 10/19/2021 6:51 PM, Nigel Johnson Ham via cctalk wrote:
>>>> It's just a memory board and looks like one!
>>>>
>>>> Picture here:
>>>>
>>>> https://www.mediafire.com/file/ive7i7ax6zdibv3/Screenshot_20211019_185019.png/file
>>>>
>>>>
>>>>
>>>> cheers,
>>>>
>>>> Nigel
>>>>
>>>>
>>>> On 2021-10-19 5:21 p.m., Chris Zach via cctalk wrote:
>>>>> Sounds familiar, got a picture of the board somewhere?
>>>>>
>>>>> C
>>>>>
>>>>> On 10/19/2021 12:57 PM, Nigel Johnson Ham via cctalk wrote:
>>>>>> I am trying to bring up an 11/23 system in a BA23 box, and the only
>>>>>> memory i have is an obscure Plessey one. The only identification is
>>>>>> the
>>>>>> p/n 705920 with dash-100 in white ink. By counting the chips I
>>>>>> make it
>>>>>> 4MB, but it does not respond. Since it takes the full 22-bit memory
>>>>>> space I can't see how any jumpers would change its accessibility.
>>>>>> Does
>>>>>> anybody have a manual?
>>>>>>
>>>>>> any help appreciated,
>>>>>>
>>>>>> Nigel Johnson
>>>>>>