The old challenge: HP-35 on Arduino

[sasa]

Back in June 2011, Jacques published Pietro De Luca's article in English about emulating HP-35 on Arduino:
https://archived.hpcalc.org/laporte/HP35_Arduino.htm

In November 2011, one Itallian magazine called "Jurassic News", which promotes free movement
of ideas, published the article:

https://www.jurassicnews.com/Archivio/Is...sue_38.PDF
Jurassic news - Year 6 - number 38 - November 2011, page 44

In the article, Pietro gave a challenge if someone can create the same functionality of HP35 in less space ROM on Arduino "Genuino Uno" (based on ATmega 328p).

Even GCC for AVRs improved quite a bit in years, as well as Arduino libraries, this task may still be interesting for large Arduino community, perhaps may also be an interesting exercise for some young members here.

The obvious solution is to move firmware to EEPROM and make some minor code optimization (if possible). However, as ATmega 328p have only 1K of EEPROM and MOSTEK instructions 10-bits long, this may be still interesting challenge for younger members affected in programming and electronic, which still learn and use such old, but still popular Arduino platform.

Have a nice fun!

[teenix]

Although the AVR has less memory, I can't see why this wouldn't be possible as I was able to squeeze 27 HP models onto a single PIC chip.

cheers

Tony

[sasa]

(09-27-2018 11:52 AM)teenix Wrote:  Although the AVR has less memory, I can't see why this wouldn't be possible as I was able to squeeze 27 HP models onto a single PIC chip.

There is no problem at all, just a small challenge for youngsters still learning...

From another point of view, additional savings may be in different approach to decode and execute instructions. I have not looked more explicitly in the Pietro's code, however I had a bit different approach when I made my own HP-35 emulator, which can be better or worst regarding used ROM space on this platform. The approach I made allowed much easier implementation of MOSTEK emulation for desktop application, including assembling and disassembling...

I believe Pietro made optimal algorithm respecting limited space and speed for this platform, since it was not an amateur at all in computer science in that time.

[burkhard]

(09-26-2018 08:04 PM)sasa Wrote:  In November 2011, one Itallian magazine called "Jurassic News", which promotes free movement
of ideas, published the article:

https://www.jurassicnews.com/Archivio/Is...sue_38.PDF
Jurassic news - Year 6 - number 38 - November 2011, page 44

The Jurassic News magazine looks great! I wish I could read Italian, as there seems a lot of interesting stuff in just that one issue. Thanks for passing that along.

[Maximilian Hohmann]

Hello!

(09-27-2018 12:58 PM)burkhard Wrote:  The Jurassic News magazine looks great! I wish I could read Italian, as there seems a lot of interesting stuff in just that one issue.

Finally my 20 years spent living in Italy pay off :-) Also from me thanks for sharing this great resource - I wasn't aware it existed. And best off all, the whole archive is freely accessible!

And regarding the topic, I don't really see why an HP35 should not fit in the memory of an Arduino (Uno). The Atmega 328 microcontroller has 31 1/2 kB of freely available memory, that should be plenty. Especially if "semi-intelligent" peripherials like the LCD and the serial keyboard are used like in the example above. Having to implement the driver for a 12-digit LED display and the 35-key-matrix on the same controller will of course add plenty of complication and make the task a lot more difficult.

Regards
Max

[Massimo Gnerucci]

I already downloaded all Jurassic News magazines some time ago.
Unfortunately they stopped their retro computing publications on April last year.

Sorry, I never thought to spread the voice at the time, since my mother tongue isn't so widely spoken around here...

[teenix]

(09-27-2018 12:29 PM)sasa Wrote:  There is no problem at all, just a small challenge for youngsters still learning...

From another point of view, additional savings may be in different approach to decode and execute instructions. I have not looked more explicitly in the Pietro's code, however I had a bit different approach when I made my own HP-35 emulator, which can be better or worst regarding used ROM space on this platform. The approach I made allowed much easier implementation of MOSTEK emulation for desktop application, including assembling and disassembling...

I believe Pietro made optimal algorithm respecting limited space and speed for this platform, since it was not an amateur at all in computer science in that time.

I totally agree :-) It is a great project for a beginner to create a full system like the HP35 and then to be able to put it to good use afterwards.

I downloaded the magazine article but I had to use an online translator so I don't think I got the full outline of the project.

I too had to recreate the binaries for the original code to suit the architecture of the PIC and make it more efficient at decoding each instruction. All in all, good fun.

cheers

Tony