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Full Version: "ZENROM + 2 Memory Modules" in single X-Memory module
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I have an X-Memory module that contains a "ZENROM + 2 memory modules" in a single X-Memory module. I have all of the normal ZENROM documentation, but can't find the receipt or any info on the web about how many were made of this type. I recall it cost about the same (more?) than my HP-41CX when I bought it in the 80's. Does anyone have documentation on this item they can share?
Surely it was a custom job done by some of the handcrafts of yore, those kind of arrangements were done on demand back then. Another common configuration was X-Functions and X-Memory together, or even the Extended-IO in the HP-IL housing. I think EduCalc offered that as a service too.

Apart from the fact that both items were in the same enclosure there was nothing different to them from the stand-alone items.
Yes, I have an Edu-Calc flyer from 1991.

double module conversion was $30

triple was $55

HP-IL + either a Development, Extended I/O or Plotter was $45

It looks like they had an arrangement with S.O.S. to do the actual work. There was a 1 year warranty too.


I have an Extended Functions + 2 Extended Memory, but I don't recall if I had the S.O.S. conversion, or one of the advertised ones in the PPC Journal.


I don't recall, but I'll keep looking thru my collection, if anyone was doing modules internal to the 41 body itself. Seems like individuals have done some on there own, but I haven't found an advertised service from back then.
I recall (vaguely) a good article in the PPC Journal (I think) that was a great reference for where everything was locatable in regards to HP41 modules and how the addressing scheme worked.

Seems like a Time module could be in any port and wired to appear to the processor as though it were in any other port (maybe that applied to all modules?) there was a rule about where Extended Memory modules could go, or you had to observe that rule if they were de-cased and wired inside the calculator housing, certain modules had the same ROM numbers but I don't recall how you knew before hand which combos were bad (this was important if you wanted to put 2 ROMs in the same housing).

I'm looking through the archives here, but it is so easy distracted and wind up reading some very interesting, but not what I had actually started out looking for in the first place.
(03-04-2015 12:56 AM)TASP Wrote: [ -> ]...so easily distracted and wind up reading some very interesting, but not what I had actually started out looking for in the first place.

I hate it when that happens.
I love it when that happens.

Almost every day.
LOL !

How do the curators here ever get what needs done with so much interesting stuff about distracting them away from the task at hand ??


Wish I had pulled my stuff out of storage 5 years ago, I might be up to speed now if I had.
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