Pdp11/23+ EPROM upgrade

Johnny Billquist bqt at update.uu.se
Fri Feb 6 04:11:54 CST 2015

On 2015-02-05 19:49, Roe Peterson wrote:
> I want to update the EPROMs on my 11/23+, which currently has 2716s.  I'm going to need 64k chips, and I understand 2764s won't work on this board.
> What are my replacement options?  I have a fairly capable programmer, it can probably handle anything with 64k capacity.

??? I don't get it.
64K chips? The 11/23 currently uses the 2716, which is what? 2K (bytes)? 
I doubt there are any more address lines going to that chip in the first 
place, and second, the memory is mapped in the I/O space which have a 
total of 8K, and that should cover not only the boot rom, but also all 
CSRs of all devices you have in the machine. A 64K chip is going to be 
totally meaningless.

So why are you looking for a 64K chip? (27512 I would assume that would 


Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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