Does anyone know where to get Zeprom's (eproms) - they were made by Zengrange.


No, they're pretty scarce. I purchased a fantastic
combination Zeprom-programmer/Psuedo-ROM box last year,
but alas the Zeprom that came with it was dead, and I
haven't been able to locate one since. They're out there,
but either in the hands of collectors, or else sitting
in the drawer of owners who don't know that they're
anything special.

I have a standing offer to pay a very generous price for
a working Zeprom, or trade for one of my more desireable
HP-41 items (such as a Diagnostic ROM). Any takers?



What is so special about a ZEPROM? Have they been coded with unique programs or have they got a special programming method?

What is stopping you using a standard(ish) EPROM?

Sorry but I've never heard of zeproms, I assume it is a trading name.


Simply put, a Zeprom is an EPROM in an HP-41 module case
that to the HP-41 looks exactly like a 16K module (two
bank-switched 8k modules), but can be erased as a normal
EPROM (little glass window in the module) and programmed
using the Zengrange voltage-convertor attachment directly
in the HP-41 (or using the Zeprom programmer I have). It
was made by Zengrange, so yes, Zeprom is a trade-name.

It is not trivial to interface a standard EPROM to the
HP-41's weirdo 56-bit serial bus, so there's a fair amount
of drive-electronics in a Zeprom in addition to the EPROM.
They are ideal if you want to try out machine-language
programming for the HP-41 and actually want to use the
programs in the field where a psuedo-ROM box might not be
so convenient.



Hello Grant,

do you have the heavy Zeprom burner with eight slots and LCD? (Weight is some pounds;-)

I have one of these, but no manual/specs or remote software.



My Zeprom Programmer was made by Firmware Corp., and has
two programming slots. No display (some LEDs). It's
about the size of an HP-41 manual, and pretty light. Is
the one you're talking about from Zengrange?



Hi Grant,

do You know any source where to buy zeproms



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