HP-71b - what to look for when buying



#2

I am going to take the plunge and get a 71b to play with. I wouldn't call myself a collector - I just like playing with old calculators. So usability is more important to me than aesthetics or rarity.

As I have started looking around on the auction site, I see a very wide range of prices. More importantly, i see people mentioning ROM versions, untampered with rubber feet, and other features which I'm not sure are important or not.

Could the 71b experts here let me know if there are any key things to be looking out for. For example, does ROM version matter? Are there any common problem areas to be careful about? What are the "must have" accessories?

Thanks in advance.


#3

Must have: HP-IL and RAM (as much as you can get).

Desirable: MATH-ROM (can be overcome with enough RAM and HP-IL, see here!)


#4

Marcus, how do you typically use the HP-IL?


#5

Quote:
how do you typically use the HP-IL?
It is used for virtually all interfacing to the outside world, including, but not limited to:

mass storage (although with enough memory, you can keep everything you commonly use in the computer at the same time and almost never need to access mass storage

printers

video display

lab instrumentation, virtually unlimited through the HP82169A HPIL-to-HPIB (IEEE-488) interface converter

RS-232, through the HP82164A or FSI164 converters

parallel, through the HP82165A or __ (I can't remember the number of the other one or two that were made)

The "L" stands for "loop." The module has an output to the first device on the loop, which also has an input and output port, and its output goes to the second device and so on, until the last device's output comes back to the 71's HPIL module's input. Auto addressing gives a unique address to every device on the loop. Every device knows what class of device it is, what its model number is, what it can do, etc.. Control can be passed from one controller on the loop to another. As you can see, there's a lot of intelligence built in. This interfacing ability, especially for lab instrumentation like signal generators, programmable power supplies, DMMs, relay matrices, RF network analyzers, etc., is why I originally got the 41. The 71's HPIL is about 30 times as fast as the 41's.

#6

Garth has explained how HP-IL works. It's the 'networking' interface of old. Connect it to a PIL-BOX (by JF Garnier) and you get PC connectivity.


#7

Thanks Garth and Marcus. I think it is very unlikely I would use most of the HP-IL devices, with the exception of connection to the PC. (Out of curiosity, when you transfer programs to the PC, what format are they in?)

Do you know if the Pil-Box is still available to purchase? It looked as if the web site had not been updated in a while so I could not tell.


#8

The file format is either a disk image file or a LIF file. Look at J-F's emulators for details.

I don't know any details about the availability of the PIL-Box. I don't have any other HP-IL devices either but it's the only means of getting data into and out of the 71 except the keyboard and the card reader neither of which can transfer data to or from a PC. With a PIL-Box (or the older HP-IL ISA card) you get a mass storage device of essentially unlimited capacity.


#9

You can get it here:
PIL Box. I got one not too long ago. Works quite well :)

#10

Just my opinion:

a) Avoid any corrosion in battery contacts
b) I dont't have it, but Math ROM seems to be close to be "a must"
c) HP-IL module may be interesting to obtain
d) Memory (RAM) modules are also interesting to obtain
e) Card reader may be interesting or not, depending on what you plan to do.
f) Aesthetics and completeness of original accessories should be welcome.
g) Obtain a complete manual, at least in electronic form.

After many years, I took the plunge and (during HHC2011) bought a nice HP 71B from a prominent collector and PPC member, to whom I'm very thankful. It doesn't have the Math ROM, nor extra memory. I don't miss the carrying case or AC adapter a lot, I just use it with AAA batteries.

I have had little time to do anything but the most basic things. Overall, I found it less interesting than I expected: Operation seems too slow, CALC mode is of little value for a die-hard RPN user like me, and the single-line display is too limiting.

Again, this is just my opinion. Please disregard any idiomatic mistake.

Edited: 14 Feb 2013, 2:20 p.m.


#11

Quote:
e) Card reader may be interesting or not, depending on what you plan to do.

The problem with the card reader is that the (long) cards are almost impossible to find. I would rather look for an HP-IL tape drive (the drive can be found really cheap, but the tapes are rare and expensive) or even better an HP-IL floppy drive.


#12

Quote:
... the drive can be found really cheap, but the tapes are rare and expensive ...

Just for curiosity: where? I observe the drives being expensive, and the tape cassettes look like the old dictaphone ones.

d:-?


#13

Hello!

Quote:
Just for curiosity: where? I observe the drives being expensive,..

Over the years I bought several of them on eBay and never paid more than 30 Euros for each. I know for sure because 30 Euros is my personal "hard limit" for any calculator accessory. But you are right: The few of them that are listed now are very expensive (over 300$) - ridiculously expensive even!

Quote:
... and the tape cassettes look like the old dictaphone ones.

They look like them, but are sufficiently different to attract crazy bids on eBay!

Regards
max

#14

Quote:
I am going to take the plunge and get a 71b to play with. I wouldn't call myself a collector - I just like playing with old calculators. So usability is more important to me than aesthetics or rarity.

Play with an emulator first. Then you'll know what you want/need.

#15

It is good advice and I have played with the emulator, and I am somewhat familiar with Basic based calculators because one of the Sharps took me through university in the 1980s.

Unfortunately, if I am honest with myself, I don't "need" the 71b or anything related to it. However, what I "want" is a new toy, in my hands, and in that regard the emulators are very unsatisfying and not very good at predicting the satisfaction one will get from the real product.

My question simply had to do my wanting to avoid a bad purchase rather than trying to be too analytic about my needs.


#16

Quote:
and I am somewhat familiar with Basic based calculators
The BASIC in the 71, especially with the Math module and lots of language-extension (LEX) files loaded from the user groups, is far and away better than any other BASIC I've seen. You can type in lines of code with no spaces (in most cases) and it will figure out what you wanted, and catch syntax errors before you try to run it. You can have any number of programs in memory at once, any number of files, and any program or subprogram can call any other one, even itself (recursively), as the subprograms set up their own environments. I wrote a very flexible text editor that I used a lot on mine that let me have over 60 files open at once. After I learned this BASIC and had a lot of free LEX files in RAM, I was introduced to other BASICs and had to work for awhile with even HP BASIC 5.1 (Rocky Mountain BASIC for instrument control) and was extremely disappointed. The 71's was way better. I think HP's Rocky Mountain group could have learned a lot from their Corvalis group. The Math module is quite a performer too. For example, it could do a 1K-point complex FFT twice as fast as the original IBM PC running GW-BASIC could. It handles complex numbers seamlessly. Of course all this is not even the tip of the iceberg. I'm just saying this is not the BASIC you've known. It's a whole new world.

#17

I'm a software developer, so I am always involved with lots of code. However it has been many many years since I did anything meaningful with BASIC and I'm looking forward to learning the 71s flavor.

I usually try to pick some non-trivial project as a forcing function to help me really learn a new language/platform. With the 15c it was the sudoku solver. Now I just have to actually buy the 71 and pick a project.


#18

Quote:
I usually try to pick some non-trivial project as a forcing function to help me really learn a new language/platform.

Here is an example of an unusual problem solved with help of the HP-71B BASIC:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=116905 (See message #61, by Egan Ford).

Here are some articles by Valentin Albillo that might interest you:

Long Live The HP-71B !

HP-71B Math ROM Baker's Dozen (Vol. 1)

HP-71B Math ROM Baker's Dozen (Vol. 2)

HP-71B Fantastic FOUR

HP-71B Minimax Polynomial Fit

Boldly Going ... Identifying Constants

Small Fry - Primes A'counting

HP-71B Short & Sweet Sudoku Solver

HP-71B Sudoku Solver's Sublime Sequel

HP-71B Sudoku Generator & Coach

HP-71B Modest Mater


#19

Thank you very much for the collection of links!

I had not seen all of them, but it was seeing some of Valentin's articles and his posts in this forum that inspired me to want to play with the 71b.

#20

Gerson, thanks for reminding me of this

Short & Sweet Math Challenge #19
. It made me look at the various solutions and I wondered what I was doing then:

Quote:
After a little magic

What? So I checked with WolframAlpha and noticed that I made a mistake. The correct formula is:


The coefficient to use with N5 is:

7 ENTER 960 /
STO 5

Fortunately it doesn't have a noticeable effect on the result.

Cheers

Thomas


#21

Hello Thomas,

Quote:
Gerson, thanks for reminding me of this

Short & Sweet Math Challenge #19
. It made me look at the various solutions and I wondered what I was doing then:

Same here. I've decided to write an RPL version for A- starting from scratch:

%%HP: T(3)A(D)F(,);
DIR
FISCHER
\<< 10, DUP LN * \Gb NEG 2, 11,
FOR n DUP n GET n NEG ALOG * n Zeta * ROT + SWAP
NEXT DROP
\>>
\Gb
\<< { 10, } 2, 11,
FOR n 0, SWAP n 2,
FOR k n k COMB n k - 1, + ALOG k ALOG - 1, + * SWAP DUP n k - 1, + GET ROT * ROT + SWAP -1,
STEP n DUP ALOG 9, - * ROT NEG 11, n ^ n ALOG - 10, * + SWAP / +
NEXT
\>>
Zeta
\<< 1, - DUP 1, SWAP PSI SWAP ! / DUP SIGN *
\>>
END

<< FISCHER >> TEVAL --> 22,9206766192
s:4,7817

Considering Valentin's HP-71B program finds this answer in about 20 seconds this HP 50g program is somewhat slow. The beta subprogram alone takes about 2 seconds, perhaps an optimization attempt should start here.

The program is just an implementation of the formula in page 2 of Thomas Schmelzer and Robert Baillie's paper:

http://eprints.maths.ox.ac.uk/1106/1/NA-06-17.pdf

I have no idea why this formula works, however.

Cheers,

Gerson.

#22

I've been poking through the Challenge #19 thread and I must say that this is a pretty hard-core group here. Definitely one of the most cerebral forums I have come across!!!

#23

Quote:
With the 15c it was the sudoku solver.

Just noticed you recently posted the article
1220: Sudoku Solver for the HP-15c.

Thanks

Thomas

#24

As to the various versions of the 71B, I note that that was discussed here:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv015.cgi?read=84027

I note also that J-F Garnier's page about versions and bugs has been flagged as an "attack page," according to my Mac's security system, and I chose not to visit.


#25

I'd rather trust JFG than a Mac.

:-)

#26

Don't use the old link to lycos (it should be just a redirection but may have been corrupted since then), use my present site at: http://www.jeffcalc.hp41.eu/
which is safe!

J-F

#27

Forth/Assembler ROM for sure I think


#28

Can that one be put in the new FRAM module someone is introducing? I ask because the Forth/Assembler module has to take a fixed address space and can't be moved around the memory map like other modules can.


#29

Yes, FRAM71 can allocate a dedicated part of the nonvolatile RAM to a fixed address to accomodate the FORTH ROM image. Besides that, it also supports 64kByte memory blocks now.

hans

http://www.flickr.com/photos/75954327@N05/sets/72157630019565381/


#30

Please apologize my ignorance, but does this mean that one can get access to the contents of the FORTH/ASSEMBLER module without having to pay the skyrocket prices demanded for it on TAS?


#31

FRAM71 will be shipped "empty", with no pre-installed images. however, it accepts the module ROM dumps (*.DMP) that are already available with the various HP-71B emulators, as well as the system ROM dumps.

hans


#32

Danke!

d:-)

#33

Excellent!


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