The PDP11/04 has landed..

Jon Elson elson at
Mon Feb 8 10:58:06 CST 2016

On 02/08/2016 09:28 AM, tony duell wrote:
>>> First week on the job in March 1980, my new boss brought me two pdp11/04s
>>> and a box of memeory chips.  He to told me to double the memory in
>>> the two computers by populating all the empty holes on the memory boards.
>> I had a boss in 1987 that asked the same of me...
> I heard that when Bristol University physics department got its first VAX (an 11/750,
> somewhat before my time), it was cheaper to buy 256K memory boards full of 16K RAM
> chips, clip them out, clean out the holes and solder in 64K RAMs rather than to buy 1MByte
> boards full of 64K RAMs from DEC. And that is what they did....
I assume they didn't buy a service contract with that 
machine?  I doubt DEC would be real happy with that.  Also, 
the 64K RAM chips need an extra address pin, were the boards 
laid out with that signal already in place?

(I seem to recall on the VAX 11/780 they had different array 
boards and memory controller when going from 4K to 16K DRAM 


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