Who wants a new printing HP-42s?

[Dave92F1]

My favorite calculator is the 42s. I use Thomas Okken's 42s on my phone every day.

On my desk is a HP-97 that is dying.

And as far as I can tell, nobody in the world is building new scientific printing calculators (let alone RPN ones).

So - I want to build a printing 42s. It would have:

* 3D printed case
* OLED display
* Thermal printer from a cash register
* Run Okken's 42s ( http://thomasokken.com/free42/ )

This would be mainly for desktop use, but it could have batteries too.

I think the whole thing could be done for a parts cost of around $100. (If we're going to sell them we'd have to charge several times that amount.)

WHO WANTS TO HELP? I'm willing to put some money into this, and do some of the work, but it's too much for me alone.

We could even run a Kickstarter and put the thing into production, if there's enough interest.

If not, we can make a few for ourselves.

Some details of my thinking:

* Runs off a USB-C power brick
* Has 4xAA NiMh cells for portable use (charges off the USB)
* USB stick interface for storing/moving programs
* Some minor enhancements from Byron Foster's 42s version on the iPhone - mainly display of all 4 registers (x, y, z, t, not just x and y)
* It could run on a Raspberry Pi 3 or similar (main issue from my viewpoint is boot time)

Here's what I can contribute:

* I'm pretty good at PCB design and know how to get them manufactured
* I can put some $$ into getting this going
* I have a 3D printer (but I'm not good enough with 3D design to design a nice-looking case)
* I can hack the 42s code if I have to (but would rather somebody else did that)

ANYBODY INTERESTED?

[Massimo Gnerucci]

Are you aware of the upcoming DM42 from www.swissmicros.com? It runs Free42 on a 400*240 screen, about 50 times faster than HP42S, stainless steel housing...





I have one beta unit in my hands, I/R printing is currently not active but should be available in one of the next firmware updates.

[Dave92F1]

No, I hadn't heard. That's fantastic.

Now I just need a printer for it (ideally with some kind of housing to make it all one unit).

So maybe it's just building the printer and a case... Should be relatively trivial.

Do you have a contact for the people building it?

--- Edit:

I just watched the video. It's a shame about the way they implemented the register display. Byron Foster's method on the iPhone is much nicer (they should look at it!).

But I suppose we'll all have our nitpicks and preferences about the way things "should" be done. It's minor.

Is there a AC power input?

Do they plan to release source code so we can hack/modify/improve it?

I'm thinking it would be great to have a case/printer/OLED display module the thing slips into, so when you have AC power you get an illuminated display and printer, but can pop it out and use it portably when you want.

[Massimo Gnerucci]

(06-13-2017 07:08 PM)Dave92F1 Wrote:  No, I hadn't heard. That's fantastic.

Now I just need a printer for it (ideally with some kind of housing to make it all one unit).

It should be compatible with HP-82240A/B

(06-13-2017 07:08 PM)Dave92F1 Wrote:  Do you have a contact for the people building it?

http://www.swissmicros.com/

(06-13-2017 07:08 PM)Dave92F1 Wrote:  I just watched the video. It's a shame about the way they implemented the register display. Byron Foster's method on the iPhone is much nicer (they should look at it!).

But I suppose we'll all have our nitpicks and preferences about the way things "should" be done. It's minor.

UI is currently under improvement. It should be possible to use part of the screen as a virtual printer. And more...

(06-13-2017 07:08 PM)Dave92F1 Wrote:  Is there a AC power input?

No, USB power and data connection. CPU jumps from 24 to 80MHz when connected.

(06-13-2017 07:08 PM)Dave92F1 Wrote:  Do they plan to release source code so we can hack/modify/improve it?

They have to, for the Free42 implementation. Not so for the underlying OS.

(06-13-2017 07:08 PM)Dave92F1 Wrote:  I'm thinking it would be great to have a case/printer/OLED display module the thing slips into, so when you have AC power you get an illuminated display and printer, but can pop it out and use it portably when you want.

Nice ideas, please share them with Michael!

[Dave92F1]

(06-13-2017 09:35 PM)Massimo Gnerucci Wrote:  UI is currently under improvement. It should be possible to use part of the screen as a virtual printer. And more...

I want a paper printout - something I can tear off and staple to something. An emulator for the HP IR printer based on a $5 cash register mechanism shouldn't' be difficult, I think.

The data to drive an OLED display (probably just the exact same data that drives the LCD) needs to be exposed on a connector at the top. As does the USB for power.

(06-13-2017 09:35 PM)Massimo Gnerucci Wrote:  Nice ideas, please share them with Michael!

I emailed "David" there. Should I be talking to Michael?

[Matt Agajanian]

This is an excellent idea. Few thoughts I'll add.

Not certain if HP will consider RPN marketability (It's lucky we still have the 35S and 50G available).

Secondly, between Flash RAM, USB connectivity, WiFi, and SD/Memory Stick/Compact Flash external storage, we have the means to build the 42S into the calculator it should have been.

So, it seems we may need to consider another WP-34S kickstarter project. I just saw the video and I'm impressed! So, Swiss Micro might be able to give it a go.

[Dave92F1]

(06-13-2017 10:15 PM)Matt Agajanian Wrote:  This is an excellent idea. Few thoughts I'll add.

Not certain if HP will consider RPN marketability (It's lucky we still have the 35S and 50G available).

Secondly, between Flash RAM, USB connectivity, WiFi, and SD/Memory Stick/Compact Flash external storage, we have the means to build the 42S into the calculator it should have been.

So, it seems we may need to consider another WP-34S kickstarter project. I just saw the video and I'm impressed! So, Swiss Micro might be able to give it a go.

Re HP, their current (2017) calculators are, IMHO, crap. For one thing, the keyboard scanning is so slow they miss keypresses unless I slow down. None of the classic calculators had that problem. The problem is that HP today is marketing to school kids, not to professionals - cost cutting, quality suffers.

A Kickstarter makes sense if we need to raise money, or fund commercial production. For a few dozen for enthusiasts, I think a kit of parts and 3D printed cases are the way to go. For that you just need people to put in time designing it. But not money.

[Massimo Gnerucci]

(06-13-2017 10:05 PM)Dave92F1 Wrote:  I want a paper printout - something I can tear off and staple to something. An emulator for the HP IR printer based on a $5 cash register mechanism shouldn't' be difficult, I think.

You will, by the I/R led. Building that $5 printer from ready-made components could be a little more difficult, methinks.

(06-13-2017 10:05 PM)Dave92F1 Wrote:  I emailed "David" there. Should I be talking to Michael?

No, that's the "D" in DM, as Michael is the "M" ;)

[Paul Dale]

(06-13-2017 10:05 PM)Dave92F1 Wrote:  I want a paper printout - something I can tear off and staple to something. An emulator for the HP IR printer based on a $5 cash register mechanism shouldn't' be difficult, I think.

If you are considering a case for the calculator and printer, would it make more sense to wire the output LED to the printer mechanism directly? Perhaps via an opto isolator.


Pauli

[Dave92F1]

More thoughts on this:

I think the proper description for what I have in mind is a "desktop dock" for the DM42P.

Here's a video of an extremely crude mockup I made last night (out of paper!):

https://goo.gl/photos/siNHjKi6pJ9SNy816

The dock would:

1 - Angle the calculator toward the user, more suitable for desktop (vs. handheld) use.

2 - Have a printer

3 - Have a backlit color TFT LCD display duplicating what's on the calculator's LCD, but angled at 30 to 45 degrees toward the user for desktop use. (See how the HP-97 display is angled for comparison.)

4 - Maybe, have batteries so the whole docked device can be portable (I really don't need this but other people might want it).

To make this work, the top of the calculator needs to have connectors that fit the dock, including:

A - DC power input (probably USB)

B - IR (or wired) printer output

C - Display data output (to drive the angled display)

Item C seems the most challenging (I suspect that isn't available now).

[mfleming]

(06-14-2017 02:47 PM)Dave92F1 Wrote:  A - DC power input (probably USB)

B - IR (or wired) printer output

C - Display data output (to drive the angled display)

Item C seems the most challenging (I suspect that isn't available now).

All three of these could be done if the DM42 could act as a USB Host. That possibility would depend on the capability of the SoC chosen for the calculator. If limited to the role of USB device, the DM42 could present itself as an HID to a controller embedded in the desktop case.

~Mark
Addendum: Or just extend the serial console to accept commands to redirect printer output and display state to the serial output.

[Matt Agajanian]

On the feature of printer output, would a non-thermal printer for permanent copy be able to be housed in at least a 42S (82240A) casing? Or, to keep the printer portable, are we restricted to thermal option?

[lemontea]

If a good way to produce 3D printed keys (mechanism, switches, etc) is figured out, we can use that for other calculator reproductions/resurrections, such as the 48G series.

Everything else inside the case can be almost the same except for the firmware.

I expect in 10 more years, this can be done, but not sure about current status of 3D printers (especially the more affordable sub-$500 ones). I don't have a 3D printer but will get one sooner or later. Right now the most affordable one seems to be the Monoprice one at around $200 and supposedly it is "not bad".

[ziggurat29]

If you want a wired printer on this particular calculator, it might be easiest to achieve via the chip's OTG support, and use a garden-variety USB printer. That way the calculator doesn't incur a hardware change (it does incur a firmware change, but that's much easier to do after-the-fact), and should open a world of existing printers without needing to try to build one from scratch.

[lemontea]

I just searched for USB thermal printer and this was the cheapest one that came up

https://www.amazon.com/dp/B06XW8MK6W/

Specifications
- Printing Method: Thermal line printing
- Print Speed: 90mm/sec
- Reliability Print: 100km
- Printing density: 384dot/line
- Paper Width: 57.5 ± 0.5 mm
- Roll Diameter: 50mm
- Paper Type: Thermal Paper
- Print parameters: support download Logo trademark print
- Character size: ANK Character, Font: A: 12 x 24dots, 1.5(W) x 3.0(H) mm
- Simplified/Traditional: 24 x 24dots, 3.0(W) x 3.0(H) mm
- Characters: 24 x 24 dots, support 18030 large font library
-Western language: ASC11 12 x 24 dots
- Interface: USB / COM / LPT / LAN
- Power: DC 12V/3A
- Cash Drawer Control: DC 12V/1A

Broad Compatibility
suits for Win 9X / Win 2000 / Win 2003 / Win XP / Win Vista / Win7 / Win8 / Win10 / Linux, compatible with ESPON, SAMSUNG

Package Contents
- 1 x Esky Thermal Printer
- 1 x Printer Driver
- 1 x Power Adapter
- 1 x USB Cable
- 1 x Thermal Paper Roll
- 1 x User Manual

[ziggurat29]

(06-15-2017 09:09 PM)lemontea Wrote:  I just searched for USB thermal printer and this was the cheapest one that came up
https://www.amazon.com/dp/B06XW8MK6W/
...
Package Contents
- 1 x PEsky Thermal Printer
...

Hmm, at usd$30 and free shipping, relative to ~usd$50 for a used 82240 on ebay, you might could even just make an HPIR-to-USB adapter, thereby turning that printer (or others) into a 82240-compatible for roughly the same cost. No battery opeartion, though.
It's not handsome, but it is cheap. Probably quieter and faster; I think it is a line printer.

[mfleming]

Check out the document by Martin Hepperle at this link

http://www.mh-aerotools.de/hp/red-eye/

Having built this project, I can attest to the relative ease of construction and availability of parts. An Arduino Pro Mini decodes the Redeye IR protocol and outputs the received characters over its serial port. All that is missing is a function to convert the Redeye characters to those the printer can handle.

The IR receiver/transmitter unit is a bit harder to find and a bit more expensive, but I'm sure someone can come up with a suitable replacement design!

~Mark

[ziggurat29]

(06-18-2017 02:20 AM)mfleming Wrote:  Check out the document by Martin Hepperle at this link
http://www.mh-aerotools.de/hp/red-eye/
Having built this project, I can attest to the relative ease of construction and availability of parts. An Arduino Pro Mini decodes the Redeye IR protocol and outputs the received characters over its serial port. All that is missing is a function to convert the Redeye characters to those the printer can handle.
The IR receiver/transmitter unit is a bit harder to find and a bit more expensive, but I'm sure someone can come up with a suitable replacement design!
~Mark

Thanks for the link; actually, that should be child's play with a couple tweaks:

1) if you're going this route, forget about the USB version of the printer, just get the serial version. They still make those, and its so much easier to interface with from a microcontroller. If you were to do this, then you could probably use a 'blue pill' board (about usd $2-3 on ebaty). (That board is not suitable for USB hosting, alas, because it has an 'F103 processor. It would need an 'F105, though you could rebrain it since those are pin-compatible.)

2) I myself would not have used the external IR adapter. Their point is well-made regarding the TSOP-xxx devices -- coincidentally I had done the same a couple days ago(!) for an unrelated activity involving an 82240 printer -- but they actually can work if you're careful. But really, making the receiver circuit from scratch is pretty trivial, too: IR encapsulated phototransistor, some passives, and maybe a schmidt trigger. (I had to do this myself for the aforementioned project since I needed to see the raw, modulated, signal, rather than the integrated-and-shaped-up one).

[Luigi Vampa]

Just FYI, USB+BT portable thermal printer just $31 (shipping included) from TAS.
Printing from Free42 could be really simple and cheap.

[EDIT] I have removed "RS-232" in this model, it is just "USB+BT" as well noted in the next post below. Thanks Dave.

[Dave Britten]

(06-20-2017 02:05 PM)Luigi Vampa Wrote:  Just FYI, USB+BT+RS232 portable thermal printer just $31 (shipping included) from TAS.
Printing from Free42 could be really simple and cheap.

Dang, that's tempting. I'm not seeing RS-232 in the listing, though. Would be nice to have something like this for my 200LX, especially if it could do plain old Epson FX-80 or LaserJet emulation.