Hand-wired core for ROM?

Brent Hilpert hilpert at cs.ubc.ca
Fri Apr 10 16:20:12 CDT 2015

On 2015-Apr-10, at 12:29 PM, Brent Hilpert wrote:
> On 2015-Apr-10, at 9:32 AM, geneb wrote:
>> On Fri, 10 Apr 2015, William Donzelli wrote:
>>> You should probably cut him a little slack, since core and rope are
>>> easily confused, as they are so similar. Rope could be rewired in the
>>> field, but I certainly would not want to be the FE with that job.
>> Yeah.  I think I'm just going to walk away from it. :)
> Core RAM and "core rope" ROM sure are often confused, but technically I would disagree that they are similar.
> . . . .
> Strikes me as conceivable that DEC used a field-configurable core rope design for the PDP-14 program memory - something like the PDP-9 module that Mattis linked to could be field alterable, but it sounds like "joe" in the OP thread may be confusing things.

This 1969 PDP-14 manual from bitsavers indeed describes a core rope ROM implementation for the control memory:


It indicates the initial programming was generally done by specification to the DEC factory, but in-the-field reprogramming was also done.

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