Was there ever an HP-71?



#2

I notice that on the cover of my HP-71B Owner's Manual there is a photo of an HP-71 that does not have the 'B' designation.

Was there ever an HP-71, without the 'B'? Just curious. If so, what was the difference?


#3

I don't think there ever was a production machine called an HP71. But it's not uncommon for the machines shown on the front of manuals/books to be slightly different from the machines that were
actaully sold. For example many of the HP75 solution books show a machine with a slightly different keyboard layout to the HP75s that were shipped.
From the PCB layouts and hardware IDS, it appears that a 4K HP71 was possibly planned. There's space on the PCB for a link to
complete the configuration chain if only 1 RAM hybrid is soldered to the PCB (instead of the 4 in every standard HP71B, giving 16K RAM). Perhaps a machine
with less memory was planned at one point.


#4

One more question. I have several of these 71Bs and most are similar. But I have one that was made in the first year and has an all plastic back.

I don't think I have ever seen an all plastic back. How long were these produced with the all plastic back?


#5

As far as I know these are newer redesigned machines with updated ROM versions. The ones with the metal backplate have ROM version 1BBBB. Then came ROM version 2CCCC with the all plastic back. ROM 2CCCC is very hard to find as there were bugs and not produced for long time. The latest ROM is 2CDCC and again has all plastic back. The newer ROM machines appear seldom. Fortunately I've got one of these :)


#6

Hi,

Daniel Diggelmann posted:
>
> The newer ROM machines appear seldom. Fortunately
> I've got one of these :)


I've never been able to find a list or description of which bugs were present in 71B's with ROM version 1BBBB.
I feel they can't be anything serious, as I've been using such a 71B for the last 15 years and never ever stumbled upon one, but I would be curious to know.

On the other hand, I do have a sheet from HP detailing the very nasty bug in version 1CCCC, which had
to do with DIMensioning and DESTROYing of arrays having the same initial letter in their name as non-array variables.
That bug could corrupt memory very badly as was quite easy to bring about.

But no such sheet for rev. 1BBBB. Could someone please shed some light on the subject ? Thanks.


#7

I know there was an article in a PPC issue. The name was "HP71 bug report". This one was clearly about the 1BBBB version.

I don't have the magazine's number and page in mind now, but maybe I'll find it in the next days...

I remember there was a lot of bugs in the UDF (User Defined Functions) routines...

#8

My all plastic versions have very early serial numbers (1st year of production: 2439Axxxxx). Incidently, I have two with plastic backs and they have sequential serial numbers. The ROM version says 1BBBB.

Or could it be that the plastic backs came out in the first year of production?


#9

Hi,

my Rev. 1BBBB HP-71's start with serial 2609A.. and 2610A.. and both have the big metal plate on the back side.
my Rev. 2CCCC HP-71 starts with serial 2737A.. and it has the 'all plastic' back.

Maybe HP had more than one production line for those machines.

Raymond


#10

Both of my all plastic back models have 2439Axxxxx serial numbers and are ver 1BBBB. My metal backs are later serial numbers.

Also, inside, my plastic back models don't have the flex circuit. They have the zebra type connector.

The two case halves are sufficiently different that they can't really be interchanged. So, I'm sure the serial number for the plastic back models have not been switched.

The serial numbers are stamped into the plastic.

I wonder where one could get a history of these. This seems to be clearly a 1st year of production (1984) plastic back, which some say, came later than the metal back versions.

The really interesting thing is that I have two, with sequential serial numbers.


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