New Multi Calculator

[Helix]

In the NP-25 board, there is the possibility to switch between a slow mode, close to the HP 25 speed, and a fast mode, about 6 times faster.
Of course, I don't know if such a feature would be possible in your board (or even desirable).

[teenix]

(10-29-2017 10:12 PM)Helix Wrote:  In the NP-25 board, there is the possibility to switch between a slow mode, close to the HP 25 speed, and a fast mode, about 6 times faster.
Of course, I don't know if such a feature would be possible in your board (or even desirable).

I can certainly understand that almost any amount of enhancements can be made to these calculators, but I prefer to keep them running as close as possible to the way they were.

I have finished the first draft of the PCB. It measures approx. 120mm x 60mm.

cheers

Tony

[teenix]

Hi all,

Just finished the first design of the PCB.

I've ordered parts and will have to wait until they all get here before I can 100% verify the board.

I'll have to populate one board before I can test the HP19c because I need some of the hardware working.

The board can be powered by 3AAA cells, or directly from the USB port of a PC.

cheers

Tony

[Dani R.]

(10-30-2017 09:24 AM)teenix Wrote:  ...
The board can be powered by 3AAA cells, or directly from the USB port of a PC.
...

Has ever somebody tried to power a LED calculator with a cell phone battery like a BL-5B, combined with a possibility to be charged over USB? So it should be possible to build a quite small package. Or are the current to high for a cell phone battery.

Dani

[teenix]

(11-01-2017 07:36 PM)Dani R. Wrote:  

(10-30-2017 09:24 AM)teenix Wrote:  ...
The board can be powered by 3AAA cells, or directly from the USB port of a PC.
...

Has ever somebody tried to power a LED calculator with a cell phone battery like a BL-5B, combined with a possibility to be charged over USB? So it should be possible to build a quite small package. Or are the current to high for a cell phone battery.

Dani

It is possible, but then there is the added cost of specialty connectors, battery charging circuitry etc. You would also have to pick a type that is expected to be around for awhile too.

cheers

Tony

[Dani R.]

I'll have a portable headphone amplifier with a BL-5B battery. They decide for this type when Nokia does not exist anymore. But there are lot of sources, on eBay and Aliexpress etc. There must be still lot of device asking for a BL-5B. But yes, the charging circuit also need place and money.

Regards

Dani

[teenix]

Hi all,

An update for the multi calculator.

The new board fired up for the first time today :-)

Apart from a dry joint on one of the surface mount parts it all worked as expected.

I have implemented storage and recall for the HP65 and HP67 and the other programmable types, HP25 etc. You can store 306 programs for the HP65 or HP67 in any order in memory, plus you can store an additional 320 programs for the HP-25, HP-38 etc in any order.

The memory has been segmented into blocks to keep things manageable. For example, 51 card files for the 65/67 can be saved to each block, or 32 programs for the other models. There is also library function where you can upload a complete block of files to and from the PC hard disk with a simple mouse click.

The image is showing one of the menu displays asking for the type of calculator you wish to use. The [P] means select Previous model in list(HP-55), or [N], the Next which would be the HP-67. Menu selection is made from the top left row of keys (same as top row in classics) and the ENTER key. The display digits are about 6mm high.

There are 21 models available and the HP10 KISS and HP19c each have a printer interface which works via the USB port to the PC.

The top switch is used for turning the calculators on or off, and if the HP19c is selected it also controls the PRGM RUN mode.

The bottom switch is (for example) the TMR/PRG/RUN for the HP55, just PRG/RUN for the other programmable models, or other functions like DEG/RAD mode for the HP21. It also controls the printer for HP10 and HP19c.

The chip is reprogrammable via the USB port so upgrading is just a mouse click.

The push buttons and switch tops are about 4mm higher than the LED displays so the should be able to protrude from a top cover for operation.

I still have some testing to finalize with storage and recall for programs keyed directly from the calculator. Hopefully won't take too long.

Wow, its been a huge job, I'm almost afraid to touch the code now in case I wreck it. :-)

cheers

Tony

[Harald]

Very nice Tony!

[BarryMead]

When will we be able to order one? Also what did you come up with regarding a case or enclosure. And lastely, what solution did you have in mind for the various key legends since it implements so many different calculators?

[rprosperi]

Amazing progress Tony, how do you find time to fly?

Do the various model calculators share the same storage space as was suggested recently? Although I can easily see some merits for this, I have assumed the complexity of implementing this isn't justified.

[teenix]

(12-09-2017 09:32 AM)BarryMead Wrote:  When will we be able to order one? Also what did you come up with regarding a case or enclosure. And lastely, what solution did you have in mind for the various key legends since it implements so many different calculators?

Hi Barry

As soon as I finish testing which I hope wont be too long.

I have bought a general purpose plastic case from an electronic hobby supplier and will see how that works. It fits the board ok but is too tall, so will have to be cut down.

The key legends will pose a problem that is not really my forte but I'll look around to see if I can come up with something.

cheers

Tony

[teenix]

(12-09-2017 01:42 PM)rprosperi Wrote:  Amazing progress Tony, how do you find time to fly?

Do the various model calculators share the same storage space as was suggested recently? Although I can easily see some merits for this, I have assumed the complexity of implementing this isn't justified.

Mixing programming and flying has had its ups and downs :-)

The PICs internal RAM implements up to 64 x 56 bit HP memory registers, plus all the GP registers. This space are shared between models.

The program storage which is just part of the HP memory, can be saved to non volatile memory in any one of 320 locations for later recall when required. The 65/67 have a different area for non volatile card storage.

cheers

Tony