Wanted: 71B ram module(s) (and maybe more?)

[badacktor]

Recently purchased an HP-71B (quick shout-out to mark fleming, for his multimod and support!) and it's been really exciting. Sadly, all I really have is the device itself and a text editor module, which is still very fun but like...I want moooore.

Most importantly, I'd like to pull down a ram module or two, honestly any size would do, even 4k, I just need a little more room. Feeling cramped.

After that, I know there are some HP-IL expansions on ebay, but the prices are just a little too rich for me. I'm not saying they're unreasonable, but if you can give me a bargin, I'd just super appreciate it.

And honestly, just anything else 71B adjacent you feel like offering, especially if it's cheap or free. Even just words of wisdom or advice.

As a quick detail, my little guy came to me in almost immaculate condition. Clearly wasn't physically used much, but also spent a lot of time under some sort of intense light. The reflective backed on the LCD has gotten a bit of a tan and even bubbled in a few places, but the keyboard feels like new and honestly, that was a slightly bigger concern in my book.

Anyway, feel free to PM with offers, advice, resources, or just some kind words. Thanks in advance!

[floppy]

I filled-up my HP71B with eBay. Look carefully. With patience. Few 32k (or more?) will appear.
Definitely not cheap "eBay HP71B RAM". One appear now in South Germany.

[Valentin Albillo]

.
Hi, badacktor,

(01-18-2023 09:07 AM)badacktor Wrote:  Recently purchased an HP-71B (quick shout-out to mark fleming, for his multimod and support!) and it's been really exciting. Sadly, all I really have is the device itself and a text editor module, which is still very fun but like...I want moooore.

Congratulations on your purchase, the HP-71B is among the best classic calculators ever released by HP, if not the very best.

Quote:Most importantly, [...] Even just words of wisdom or advice.

Have a look at this 150-page PDF document created by forum's member Sylvain Cote, featuring everything about hardware/software/misc related to the HP-71B:

HP-71B Compendium

Also, you may want to have a look at the following PDF articles I wrote which extensively discuss and/or feature the HP-71B, and also include full, documented programs for it:

Long Live the HP-71B, (full description and history, includes a Text Stereograms generator program)
HP-71B Modest Mater, (program to solve Mate-in-N chess problems)
HP-71B Math ROM Bakers Dozen (Vol. 1), (many tips and useful code snippets, first part)
HP-71B Math ROM Bakers Dozen (Vol. 2), ((many tips and useful code snippets, second part))
HP-71B Short and Sweet Sudoku Solver, (program to solve any Sudoku puzzle)
HP-71B Sudoku Solver Sublime Sequel, (enhancement to the program to solve any Sudoku puzzle)
HP-71B Sudoku Generator and Coach, (program to generate new Sudoku puzzles and coach you to manually solve any puzzle)
HP-71B Fantastic FOUR, (multiprecision multiplication using Fast Fourier Transforms)
HP-71B Minimax Polynomial Fit, (program to fit a set of data to the very best possible polynomial)
25 years of Othello, (My story with Othello, includes a program to play Othello versus the machine)
Small Fry - Primes Acounting, (routine to very quickly count primes on a given interval with excellent accuracy)
Small Fry - Let's Be Rational, (routine to convert reals to fractions and find their continued fracton form)
Boldly Going - Matrix Square Root, (routine to compute the square root of a given matrix)
Boldly Going - Identifying Constants, (program to find the symbolic expression which evaluates to a given numeric value, many applications)
HP-71B Advanced Uses of STRNGLEX, (focuses on its less known keywords, whose capabilities are described with examples aplenty)
Boldly Going - Mandelbrot Set Area, (includes a program to quickly compute an accurate estimation of Mandelbrot set's area)
Math Pac 2 - My Comments and Proposals, (details the new keywords I propose for the HP-71 Math Pac 2, a new J-F Garnier's project)
Boldly Going - Abundant but Rare, (quickly and exactly finds an interesting and rare kind of so-called abundant numbers, up to 205-digit long)
Boldly Going - Eigenvalues and Friends, (computes the Characteristic Polynomial, Inverse and Determinant of real/complex matrices)
Boldly Going - Climbing Project Euler, (my story with Project Euler, includes 7 solved non-trivial problems with full details and comments)
Boldly Going - Outsmarting PROOT (71B), (subprogram+driver to find at once all real/cplex roots of polynomials with real/cplex coeffs.)
DOMINOKU – Swiftly Solving Domino Grids, (solves a newspaper-style domino puzzle which goes by assorted names (“Domino Logic”, etc.)

Finally, there's plenty of additional programs, pictures, and other articles for the HP-71B at my HP site, look in the Sections HP Calculator Programs, HP Calculator Raw Scans and HP Calculator Pictures (includes detailed descriptions)

More than enough to keep you busy for weeks with your new HP-71B !

V.

[Siegfried]

Are there any "new" HP71B RAM options now that FRAM71 seems to be gone for good?

I just purchased one, too (via classifieds here), wait for it to arrive and plan to get MultiMOD while it lasts as all the physical ROM modules seem to be around 200€ on EBay. A bit more RAM would be nice, too.

A quick search didn't find much about the physical properties of the front RAM module to judge whether a recreation would be feasible. In the FRAM71 thread I found a mention that FRAM71 used some kind of very special (and very expensive) RAM chips.

[floppy]

https://github.com/mafleming/HP71MultiMod

MultiMod as hadware instead of FRAM71: contact Mark

[mfleming]

(01-21-2023 08:02 AM)Siegfried Wrote:  I just purchased one, too (via classifieds here), wait for it to arrive and plan to get MultiMOD while it lasts as all the physical ROM modules seem to be around 200€ on EBay. A bit more RAM would be nice, too.

The going price for original 71B ROMs was what prompted the MultiMod!

I'm happy to note that I managed to get a few PIC processors from Microchip Direct and they're on the way from the Thailand facility. I should be able to make a few more boards in a couple of weeks. See the original Classified post for order details.
https://www.hpmuseum.org/forum/thread-16448.html

I'm a bit hesitant to mention this at this early stage but I'm hoping to eventually provide RAM as well as ROM. Still very tentative, in the twiddling around stage, so don't hold your breath too long

[Siegfried]

(01-21-2023 10:21 PM)mfleming Wrote:  I'm a bit hesitant to mention this at this early stage but I'm hoping to eventually provide RAM as well as ROM. Still very tentative, in the twiddling around stage, so don't hold your breath too long

Would that be with the same hardware or require new hardware? I am quite trained at holding my breath as my HP71B hasn't even touched my hands yet ;-)

[mfleming]

(01-23-2023 03:09 PM)Siegfried Wrote:  

(01-21-2023 10:21 PM)mfleming Wrote:  I'm a bit hesitant to mention this at this early stage but I'm hoping to eventually provide RAM as well as ROM. Still very tentative, in the twiddling around stage, so don't hold your breath too long

Would that be with the same hardware or require new hardware? I am quite trained at holding my breath as my HP71B hasn't even touched my hands yet ;-)

All new hardware. I've been able to get away with doing the reflow soldering myself for the MultiMod but the new fine pitch parts will likely require an assembly house. This project is definitely a stretch beyond my familiar skill set, but then I'd never programmed a PIC before the MultiMod. As J-F can attest, I didn't know much about 71B internals either